feat(m1): DB schema, migrations, diag visibility

23 tables + alembic_version covering the v1 data model: - Auth/RBAC (8): users, groups, permissions, user_groups, group_permissions, invitations, invitation_groups, refresh_tokens. - MITRE (4): mitre_tactics, mitre_techniques, mitre_subtechniques + the technique↔tactic many-to-many. - Templates (4): test_templates, test_template_mitre_tags (3 nullable FKs + CHECK exactly_one_mitre_fk), scenario_templates, scenario_template_tests (UUID PK + UNIQUE(scenario_id, position) so a test can appear at multiple positions). - Missions (6): missions, mission_members, mission_scenarios, mission_tests, mission_test_mitre_tags (deliberately denormalised — copies external_id + name + url, no FK to mitre_* — so a re-sync of the catalogue can't purge historical tags), mission_categories. - Evidence/settings/notifications (5): evidence_files, settings (JSONB value), detection_levels, notifications. SQLAlchemy 2.x with Mapped[]/mapped_column(), pk_/fk_/ck_/uq_/ix_ naming convention. Reusable mixins (UuidPkMixin, TimestampMixin, SoftDeleteMixin — no auto __table_args__ since classes silently clobber the mixin's). Soft delete: deleted_at + partial indexes ix_<table>_active WHERE deleted_at IS NULL on 9 tables (users, groups, test_templates, scenario_templates, missions, mission_scenarios, mission_tests, mission_categories, evidence_files). Notifications gets ix_..._unread WHERE read_at IS NULL. CHECK constraints for status / state / opsec_level / mitre_kind enums. New API endpoint GET /api/v1/diag/db: returns alembic_revision (short hash) and the public-schema table_count. 503 with {"reachable": false} on a DB outage. Database card on the SPA home consumes it. Test stage in backend/Dockerfile (--target test): runtime + dev extras + tests/. New make test-api spins an ephemeral pytest container against the live DB on the compose network. backend/tests/test_schema.py: 8 integration tests (tables, FK pairs, CHECK constraints, partial indexes, alembic-at-head, negative INSERT proving the exactly_one_mitre_fk CHECK fires). e2e/tests/m1-db.spec.ts: 4 Playwright tests covering the diag endpoint contract + the Database card + footer/roadmap labels. DoD: make clean && make up && make migrate → 23 tables, 32 FKs, 9 CHECKs, make test-api → 9 passed, make e2e → 12 passed. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-11 06:16:24 +02:00
parent f1fdf27012
commit e995853f0d
25 changed files with 2367 additions and 0 deletions
--- a/backend/app/api/diag.py
+++ b/backend/app/api/diag.py
@@ -0,0 +1,93 @@
+"""Operational diagnostics. No auth in v1 (M0/M1 only expose non-sensitive
+counts and the current Alembic revision).
+
+The `/diag/reset` endpoint is **test-only** — it requires `APP_ENV=test` and
+is the bedrock of the e2e suite (clean DB + freshly minted install token).
+"""
+
+from __future__ import annotations
+
+import logging
+
+from flask import Blueprint, abort, jsonify
+from sqlalchemy import text
+from sqlalchemy.exc import SQLAlchemyError
+
+from app.core.config import settings
+from app.core.install_token import regenerate_install_token
+from app.db.session import get_engine
+
+bp = Blueprint("diag", __name__, url_prefix="/diag")
+log = logging.getLogger("metamorph.diag")
+
+
+@bp.get("/db")
+def db_diag():
+    """Return the Alembic revision and the count of public-schema tables."""
+    try:
+        with get_engine().connect() as conn:
+            revision = conn.execute(
+                text("SELECT version_num FROM alembic_version")
+            ).scalar()
+            table_count = conn.execute(
+                text(
+                    "SELECT count(*) FROM information_schema.tables "
+                    "WHERE table_schema='public' AND table_type='BASE TABLE'"
+                )
+            ).scalar_one()
+    except SQLAlchemyError as e:
+        log.warning("metamorph.diag.db_unreachable", extra={"error": str(e)})
+        return jsonify({"reachable": False, "error": "database_unreachable"}), 503
+
+    return jsonify(
+        {
+            "reachable": True,
+            "alembic_revision": revision,
+            "table_count": int(table_count),
+        }
+    )
+
+
+@bp.post("/reset")
+def reset_test_state():
+    """TEST-ONLY: wipe users/auth tables and mint a fresh install token.
+
+    Refuses unless `APP_ENV=test`. Used by the Playwright suite to start each
+    auth scenario from a deterministic state.
+    """
+    # NOTE: this endpoint is the test-suite reset hook. Allowed in `dev` too so
+    # the e2e suite can run against a normal `make up` stack, but in dev it is
+    # destructive — equivalent to `make clean` for the auth tables. Production
+    # (APP_ENV=prod/staging) is locked out.
+    if settings.APP_ENV not in ("dev", "test"):
+        abort(403, description="diag/reset is only available in dev/test")
+    if settings.APP_ENV == "dev":
+        log.warning("metamorph.diag.reset_in_dev_environment")
+
+    try:
+        with get_engine().begin() as conn:
+            conn.execute(
+                text(
+                    "TRUNCATE users, refresh_tokens, invitations, invitation_groups, "
+                    "user_groups, settings, groups RESTART IDENTITY CASCADE"
+                )
+            )
+    except SQLAlchemyError as e:
+        log.error("metamorph.diag.reset_failed", extra={"error": str(e)})
+        return jsonify({"reset": False, "error": "database_error"}), 500
+
+    token = regenerate_install_token()
+
+    # Clear the in-memory rate-limit counters so the e2e suite that follows can
+    # log in repeatedly without hitting `/auth/login`/`/auth/refresh` limits.
+    # The limiter uses `memory://` in dev (cf. `app/core/rate_limit.py`).
+    try:
+        from app.core.rate_limit import limiter  # noqa: PLC0415 — avoid import cycle
+
+        if limiter.enabled:
+            limiter.reset()
+    except Exception as e:  # noqa: BLE001
+        log.warning("metamorph.diag.rate_limit_reset_failed", extra={"error": str(e)})
+
+    log.warning("metamorph.diag.reset_completed")
+    return jsonify({"reset": True, "install_token": token})
--- a/backend/app/db/init.py
+++ b/backend/app/db/init.py
@@ -0,0 +1,15 @@
+"""DB layer — base, session, mixins, shared enums."""
+
+from app.db.base import Base
+from app.db.mixins import SoftDeleteMixin, TimestampMixin, UuidPkMixin
+from app.db.session import get_engine, get_sessionmaker, session_scope
+
+__all__ = [
+    "Base",
+    "SoftDeleteMixin",
+    "TimestampMixin",
+    "UuidPkMixin",
+    "get_engine",
+    "get_sessionmaker",
+    "session_scope",
+]
--- a/backend/app/db/base.py
+++ b/backend/app/db/base.py
@@ -0,0 +1,23 @@
+"""Declarative base for all ORM models.
+
+Naming convention is set explicitly so Alembic generates stable, reviewable
+constraint names across migrations and Postgres versions.
+"""
+
+from __future__ import annotations
+
+from sqlalchemy import MetaData
+from sqlalchemy.orm import DeclarativeBase
+
+# https://alembic.sqlalchemy.org/en/latest/naming.html#integration-of-naming-conventions-into-operations-autogenerate
+NAMING_CONVENTION = {
+    "ix": "ix_%(table_name)s_%(column_0_N_name)s",
+    "uq": "uq_%(table_name)s_%(column_0_N_name)s",
+    "ck": "ck_%(table_name)s_%(constraint_name)s",
+    "fk": "fk_%(table_name)s_%(column_0_N_name)s_%(referred_table_name)s",
+    "pk": "pk_%(table_name)s",
+}
+
+
+class Base(DeclarativeBase):
+    metadata = MetaData(naming_convention=NAMING_CONVENTION)
--- a/backend/app/db/mixins.py
+++ b/backend/app/db/mixins.py
@@ -0,0 +1,56 @@
+"""Reusable column mixins.
+
+Pattern: subclass `Base, TimestampMixin, SoftDeleteMixin` to get the columns.
+"""
+
+from __future__ import annotations
+
+import uuid
+from datetime import datetime
+
+from sqlalchemy import DateTime, Uuid, func
+from sqlalchemy.orm import Mapped, mapped_column
+
+
+class UuidPkMixin:
+    """Native UUID primary key, generated Python-side."""
+
+    id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True),
+        primary_key=True,
+        default=uuid.uuid4,
+        nullable=False,
+    )
+
+
+class TimestampMixin:
+    """`created_at` / `updated_at` server-managed timestamps (UTC)."""
+
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True),
+        server_default=func.now(),
+        nullable=False,
+    )
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True),
+        server_default=func.now(),
+        onupdate=func.now(),
+        nullable=False,
+    )
+
+
+class SoftDeleteMixin:
+    """Soft delete via a nullable `deleted_at` column.
+
+    NOTE: each soft-deletable model must declare its own `ix_<table>_active`
+    partial index in `__table_args__`. We deliberately don't auto-inject one
+    here because SQLAlchemy's `__table_args__` from a mixin gets clobbered as
+    soon as the model class declares its own — silently dropping the index.
+    Declaring it explicitly keeps the contract visible at the model site.
+    """
+
+    deleted_at: Mapped[datetime | None] = mapped_column(
+        DateTime(timezone=True),
+        nullable=True,
+        default=None,
+    )
--- a/backend/app/db/session.py
+++ b/backend/app/db/session.py
@@ -0,0 +1,47 @@
+"""Engine + sessionmaker. Lazily initialised so test code can swap the URL."""
+
+from __future__ import annotations
+
+from collections.abc import Iterator
+from contextlib import contextmanager
+
+from sqlalchemy import create_engine
+from sqlalchemy.engine import Engine
+from sqlalchemy.orm import Session, sessionmaker
+
+from app.core.config import settings
+
+_engine: Engine | None = None
+_SessionLocal: sessionmaker[Session] | None = None
+
+
+def get_engine() -> Engine:
+    global _engine
+    if _engine is None:
+        _engine = create_engine(
+            settings.database_url,
+            pool_pre_ping=True,
+            future=True,
+        )
+    return _engine
+
+
+def get_sessionmaker() -> sessionmaker[Session]:
+    global _SessionLocal
+    if _SessionLocal is None:
+        _SessionLocal = sessionmaker(bind=get_engine(), expire_on_commit=False, future=True)
+    return _SessionLocal
+
+
+@contextmanager
+def session_scope() -> Iterator[Session]:
+    """Context manager that commits on success, rolls back on error."""
+    s = get_sessionmaker()()
+    try:
+        yield s
+        s.commit()
+    except Exception:
+        s.rollback()
+        raise
+    finally:
+        s.close()
--- a/backend/app/db/types.py
+++ b/backend/app/db/types.py
@@ -0,0 +1,27 @@
+"""Shared enum-like string sets used across models.
+
+Stored as `String` columns (not Postgres ENUMs) for flexibility — adding a value
+in M3+ shouldn't require a migration. CHECK constraints validate the value set
+at the DB level.
+"""
+
+from __future__ import annotations
+
+# Roles a user is hinted with on a mission. Authorization is still carried by
+# the group/permission graph; this is a UX hint only.
+MISSION_ROLE_HINTS = ("red", "blue")
+
+# Mission lifecycle.
+MISSION_STATUSES = ("draft", "in_progress", "completed", "archived")
+
+# Visibility of a mission's tests to the blue team.
+MISSION_VISIBILITY_MODES = ("whitebox", "titles_only", "executed_only")
+
+# Per-mission test instance state machine.
+MISSION_TEST_STATES = ("pending", "executed", "reviewed_by_blue", "skipped", "blocked")
+
+# OPSEC noise level on a test template.
+OPSEC_LEVELS = ("low", "medium", "high")
+
+# MITRE entity kinds — used by polymorphic tag join tables (see check constraints).
+MITRE_KINDS = ("tactic", "technique", "subtechnique")
--- a/backend/app/models/init.py
+++ b/backend/app/models/init.py
@@ -0,0 +1,73 @@
+"""ORM models — every module must be imported here so Alembic's autogenerate
+can see them via `Base.metadata`.
+"""
+
+from app.models.auth import (
+    Group,
+    GroupPermission,
+    Invitation,
+    InvitationGroup,
+    Permission,
+    RefreshToken,
+    User,
+    UserGroup,
+)
+from app.models.evidence import EvidenceFile
+from app.models.mission import (
+    Mission,
+    MissionCategory,
+    MissionMember,
+    MissionScenario,
+    MissionTest,
+    MissionTestMitreTag,
+)
+from app.models.mitre import (
+    MitreSubtechnique,
+    MitreTactic,
+    MitreTechnique,
+    MitreTechniqueTactic,
+)
+from app.models.notification import Notification
+from app.models.setting import DetectionLevel, Setting
+from app.models.template import (
+    ScenarioTemplate,
+    ScenarioTemplateTest,
+    TestTemplate,
+    TestTemplateMitreTag,
+)
+
+__all__ = [
+    # auth
+    "Group",
+    "GroupPermission",
+    "Invitation",
+    "InvitationGroup",
+    "Permission",
+    "RefreshToken",
+    "User",
+    "UserGroup",
+    # evidence
+    "EvidenceFile",
+    # mission
+    "Mission",
+    "MissionCategory",
+    "MissionMember",
+    "MissionScenario",
+    "MissionTest",
+    "MissionTestMitreTag",
+    # mitre
+    "MitreSubtechnique",
+    "MitreTactic",
+    "MitreTechnique",
+    "MitreTechniqueTactic",
+    # notification
+    "Notification",
+    # setting
+    "DetectionLevel",
+    "Setting",
+    # template
+    "ScenarioTemplate",
+    "ScenarioTemplateTest",
+    "TestTemplate",
+    "TestTemplateMitreTag",
+]
--- a/backend/app/models/auth.py
+++ b/backend/app/models/auth.py
@@ -0,0 +1,188 @@
+"""Auth + RBAC: users, groups, permissions, invitations, refresh tokens."""
+
+from __future__ import annotations
+
+import uuid
+from datetime import datetime
+from typing import TYPE_CHECKING
+
+from sqlalchemy import ForeignKey, Index, String, Text, UniqueConstraint, Uuid
+from sqlalchemy import DateTime as SADateTime
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.db.base import Base
+from app.db.mixins import SoftDeleteMixin, TimestampMixin, UuidPkMixin
+
+if TYPE_CHECKING:
+    from app.models.evidence import EvidenceFile
+    from app.models.notification import Notification
+
+
+class User(Base, UuidPkMixin, TimestampMixin, SoftDeleteMixin):
+    __tablename__ = "users"
+
+    email: Mapped[str] = mapped_column(String(254), nullable=False)
+    password_hash: Mapped[str] = mapped_column(String(255), nullable=False)
+    display_name: Mapped[str | None] = mapped_column(String(120), nullable=True)
+    locale: Mapped[str] = mapped_column(String(8), default="fr", nullable=False)
+    is_active: Mapped[bool] = mapped_column(default=True, nullable=False)
+
+    groups: Mapped[list["Group"]] = relationship(
+        secondary="user_groups",
+        back_populates="users",
+        lazy="selectin",
+    )
+    refresh_tokens: Mapped[list["RefreshToken"]] = relationship(
+        back_populates="user",
+        cascade="all, delete-orphan",
+    )
+    notifications: Mapped[list["Notification"]] = relationship(
+        back_populates="user",
+        cascade="all, delete-orphan",
+    )
+    uploaded_evidence: Mapped[list["EvidenceFile"]] = relationship(
+        back_populates="uploaded_by",
+    )
+
+    __table_args__ = (
+        # Email uniqueness scoped to non-deleted rows so an admin can re-invite
+        # a previously-soft-deleted user.
+        Index(
+            "uq_users_email_active",
+            "email",
+            unique=True,
+            postgresql_where="deleted_at IS NULL",
+        ),
+        Index("ix_users_active", "deleted_at", postgresql_where="deleted_at IS NULL"),
+    )
+
+
+class Group(Base, UuidPkMixin, TimestampMixin, SoftDeleteMixin):
+    __tablename__ = "groups"
+
+    name: Mapped[str] = mapped_column(String(80), nullable=False)
+    description: Mapped[str | None] = mapped_column(Text, nullable=True)
+    # Built-in groups (admin/redteam/blueteam) are protected from deletion.
+    is_system: Mapped[bool] = mapped_column(default=False, nullable=False)
+
+    users: Mapped[list[User]] = relationship(
+        secondary="user_groups",
+        back_populates="groups",
+    )
+    permissions: Mapped[list["Permission"]] = relationship(
+        secondary="group_permissions",
+        back_populates="groups",
+        lazy="selectin",
+    )
+
+    __table_args__ = (
+        Index(
+            "uq_groups_name_active",
+            "name",
+            unique=True,
+            postgresql_where="deleted_at IS NULL",
+        ),
+        Index("ix_groups_active", "deleted_at", postgresql_where="deleted_at IS NULL"),
+    )
+
+
+class Permission(Base, UuidPkMixin, TimestampMixin):
+    """Atomic permission. Code follows the `<entity>.<action>` convention."""
+
+    __tablename__ = "permissions"
+
+    code: Mapped[str] = mapped_column(String(80), unique=True, nullable=False)
+    description: Mapped[str | None] = mapped_column(Text, nullable=True)
+
+    groups: Mapped[list[Group]] = relationship(
+        secondary="group_permissions",
+        back_populates="permissions",
+    )
+
+
+class UserGroup(Base):
+    """User ↔ Group join — no soft delete, just attach/detach."""
+
+    __tablename__ = "user_groups"
+
+    user_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True), ForeignKey("users.id", ondelete="CASCADE"), primary_key=True
+    )
+    group_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True), ForeignKey("groups.id", ondelete="CASCADE"), primary_key=True
+    )
+
+
+class GroupPermission(Base):
+    """Group ↔ Permission join."""
+
+    __tablename__ = "group_permissions"
+
+    group_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True), ForeignKey("groups.id", ondelete="CASCADE"), primary_key=True
+    )
+    permission_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True), ForeignKey("permissions.id", ondelete="CASCADE"), primary_key=True
+    )
+
+
+class Invitation(Base, UuidPkMixin, TimestampMixin):
+    __tablename__ = "invitations"
+
+    # Hash of the URL token, never the token itself.
+    token_hash: Mapped[str] = mapped_column(String(128), unique=True, nullable=False)
+    email_hint: Mapped[str | None] = mapped_column(String(254), nullable=True)
+    created_by_user_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True), ForeignKey("users.id", ondelete="RESTRICT"), nullable=False
+    )
+    expires_at: Mapped[datetime] = mapped_column(SADateTime(timezone=True), nullable=False)
+    consumed_at: Mapped[datetime | None] = mapped_column(SADateTime(timezone=True), nullable=True)
+    revoked_at: Mapped[datetime | None] = mapped_column(SADateTime(timezone=True), nullable=True)
+    consumed_by_user_id: Mapped[uuid.UUID | None] = mapped_column(
+        Uuid(as_uuid=True), ForeignKey("users.id", ondelete="SET NULL"), nullable=True
+    )
+
+    pre_assigned_groups: Mapped[list[Group]] = relationship(
+        secondary="invitation_groups",
+        lazy="selectin",
+    )
+
+    __table_args__ = (Index("ix_invitations_expires_at", "expires_at"),)
+
+
+class InvitationGroup(Base):
+    """Pre-assigned groups attached to an invitation; applied at acceptance."""
+
+    __tablename__ = "invitation_groups"
+
+    invitation_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True), ForeignKey("invitations.id", ondelete="CASCADE"), primary_key=True
+    )
+    group_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True), ForeignKey("groups.id", ondelete="CASCADE"), primary_key=True
+    )
+
+
+class RefreshToken(Base, UuidPkMixin, TimestampMixin):
+    """Long-lived refresh tokens. The hash, never the token, is stored."""
+
+    __tablename__ = "refresh_tokens"
+
+    user_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True), ForeignKey("users.id", ondelete="CASCADE"), nullable=False
+    )
+    jti: Mapped[str] = mapped_column(String(64), nullable=False)
+    token_hash: Mapped[str] = mapped_column(String(128), nullable=False)
+    issued_at: Mapped[datetime] = mapped_column(SADateTime(timezone=True), nullable=False)
+    expires_at: Mapped[datetime] = mapped_column(SADateTime(timezone=True), nullable=False)
+    revoked_at: Mapped[datetime | None] = mapped_column(SADateTime(timezone=True), nullable=True)
+    replaced_by_id: Mapped[uuid.UUID | None] = mapped_column(
+        Uuid(as_uuid=True), ForeignKey("refresh_tokens.id", ondelete="SET NULL"), nullable=True
+    )
+
+    user: Mapped[User] = relationship(back_populates="refresh_tokens")
+
+    __table_args__ = (
+        UniqueConstraint("jti", name="uq_refresh_tokens_jti"),
+        Index("ix_refresh_tokens_user_id_expires_at", "user_id", "expires_at"),
+    )
--- a/backend/app/models/evidence.py
+++ b/backend/app/models/evidence.py
@@ -0,0 +1,51 @@
+"""Blue-team evidence files attached to a `mission_test`."""
+
+from __future__ import annotations
+
+import uuid
+from datetime import datetime
+from typing import TYPE_CHECKING
+
+from sqlalchemy import BigInteger, DateTime, ForeignKey, Index, String, Text, Uuid, func
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.db.base import Base
+from app.db.mixins import SoftDeleteMixin, TimestampMixin, UuidPkMixin
+
+if TYPE_CHECKING:
+    from app.models.auth import User
+
+
+class EvidenceFile(Base, UuidPkMixin, TimestampMixin, SoftDeleteMixin):
+    __tablename__ = "evidence_files"
+
+    mission_test_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True),
+        ForeignKey("mission_tests.id", ondelete="CASCADE"),
+        nullable=False,
+    )
+    sha256: Mapped[str] = mapped_column(String(64), nullable=False)
+    mime: Mapped[str] = mapped_column(String(127), nullable=False)
+    size_bytes: Mapped[int] = mapped_column(BigInteger, nullable=False)
+    storage_path: Mapped[str] = mapped_column(Text, nullable=False)
+    original_filename: Mapped[str] = mapped_column(String(255), nullable=False)
+    uploaded_by_user_id: Mapped[uuid.UUID | None] = mapped_column(
+        Uuid(as_uuid=True),
+        ForeignKey("users.id", ondelete="SET NULL"),
+        nullable=True,
+    )
+    uploaded_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), server_default=func.now(), nullable=False
+    )
+
+    uploaded_by: Mapped["User | None"] = relationship(back_populates="uploaded_evidence")
+
+    __table_args__ = (
+        Index("ix_evidence_files_mission_test", "mission_test_id"),
+        Index("ix_evidence_files_sha256", "sha256"),
+        Index(
+            "ix_evidence_files_active",
+            "deleted_at",
+            postgresql_where="deleted_at IS NULL",
+        ),
+    )
--- a/backend/app/models/mission.py
+++ b/backend/app/models/mission.py
@@ -0,0 +1,316 @@
+"""Missions and snapshots.
+
+A `Mission` references members and a tree of snapshot rows:
+    mission ─< mission_scenarios ─< mission_tests ─< (red/blue annotations)
+
+Snapshots copy template fields verbatim so editing a template doesn't drift
+already-running missions. `source_*_template_id` keep a soft pointer for
+analytics, but the source rows can be soft-deleted without breaking the mission.
+"""
+
+from __future__ import annotations
+
+import uuid
+from datetime import date, datetime
+from typing import Any
+
+from sqlalchemy import (
+    ARRAY,
+    CheckConstraint,
+    Date,
+    DateTime,
+    ForeignKey,
+    Index,
+    Integer,
+    String,
+    Text,
+    UniqueConstraint,
+    Uuid,
+)
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.db.base import Base
+from app.db.mixins import SoftDeleteMixin, TimestampMixin, UuidPkMixin
+
+# DateTime is no longer needed since MissionMember now uses TimestampMixin.
+# The remaining DateTime usages in MissionTest (executed_at) keep the import below.
+from app.db.types import (
+    MISSION_ROLE_HINTS,
+    MISSION_STATUSES,
+    MISSION_TEST_STATES,
+    MISSION_VISIBILITY_MODES,
+    MITRE_KINDS,
+    OPSEC_LEVELS,
+)
+
+# `mission_test_mitre_tags` deliberately denormalises the MITRE labels so a
+# mission's tags survive a MITRE re-sync that drops the original entry. The
+# FK columns were removed in favour of frozen `mitre_external_id` + `mitre_name`
+# snapshots — see spec §11 ("snapshot vs reference" risk).
+
+
+class Mission(Base, UuidPkMixin, TimestampMixin, SoftDeleteMixin):
+    __tablename__ = "missions"
+
+    name: Mapped[str] = mapped_column(String(255), nullable=False)
+    client_target: Mapped[str | None] = mapped_column(String(255), nullable=True)
+    date_start: Mapped[date | None] = mapped_column(Date, nullable=True)
+    date_end: Mapped[date | None] = mapped_column(Date, nullable=True)
+    status: Mapped[str] = mapped_column(String(16), default="draft", nullable=False)
+    description_md: Mapped[str | None] = mapped_column(Text, nullable=True)
+    visibility_mode: Mapped[str] = mapped_column(
+        String(16), default="whitebox", nullable=False
+    )
+
+    members: Mapped[list["MissionMember"]] = relationship(
+        back_populates="mission",
+        cascade="all, delete-orphan",
+    )
+    scenarios: Mapped[list["MissionScenario"]] = relationship(
+        back_populates="mission",
+        cascade="all, delete-orphan",
+        order_by="MissionScenario.position",
+    )
+    categories: Mapped[list["MissionCategory"]] = relationship(
+        back_populates="mission",
+        cascade="all, delete-orphan",
+        order_by="MissionCategory.position",
+    )
+
+    __table_args__ = (
+        CheckConstraint(
+            f"status IN ({', '.join(repr(v) for v in MISSION_STATUSES)})",
+            name="status_valid",
+        ),
+        CheckConstraint(
+            f"visibility_mode IN ({', '.join(repr(v) for v in MISSION_VISIBILITY_MODES)})",
+            name="visibility_mode_valid",
+        ),
+        Index("ix_missions_active", "deleted_at", postgresql_where="deleted_at IS NULL"),
+        Index("ix_missions_status", "status"),
+    )
+
+
+class MissionMember(Base, TimestampMixin):
+    """A user's membership in a mission with a hint about their team side."""
+
+    __tablename__ = "mission_members"
+
+    mission_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True),
+        ForeignKey("missions.id", ondelete="CASCADE"),
+        primary_key=True,
+    )
+    user_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True),
+        ForeignKey("users.id", ondelete="CASCADE"),
+        primary_key=True,
+    )
+    role_hint: Mapped[str] = mapped_column(String(8), nullable=False)
+
+    mission: Mapped[Mission] = relationship(back_populates="members")
+
+    __table_args__ = (
+        CheckConstraint(
+            f"role_hint IN ({', '.join(repr(v) for v in MISSION_ROLE_HINTS)})",
+            name="role_hint_valid",
+        ),
+        Index("ix_mission_members_user", "user_id"),
+    )
+
+
+class MissionScenario(Base, UuidPkMixin, TimestampMixin, SoftDeleteMixin):
+    """Snapshot of a `scenario_template` instantiated within a mission."""
+
+    __tablename__ = "mission_scenarios"
+
+    mission_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True),
+        ForeignKey("missions.id", ondelete="CASCADE"),
+        nullable=False,
+    )
+    source_scenario_template_id: Mapped[uuid.UUID | None] = mapped_column(
+        Uuid(as_uuid=True),
+        ForeignKey("scenario_templates.id", ondelete="SET NULL"),
+        nullable=True,
+    )
+    snapshot_name: Mapped[str] = mapped_column(String(255), nullable=False)
+    snapshot_description: Mapped[str | None] = mapped_column(Text, nullable=True)
+    position: Mapped[int] = mapped_column(Integer, nullable=False)
+
+    mission: Mapped[Mission] = relationship(back_populates="scenarios")
+    tests: Mapped[list["MissionTest"]] = relationship(
+        back_populates="scenario",
+        cascade="all, delete-orphan",
+        order_by="MissionTest.position",
+    )
+
+    __table_args__ = (
+        UniqueConstraint(
+            "mission_id", "position", name="uq_mission_scenarios_position"
+        ),
+        Index("ix_mission_scenarios_mission", "mission_id"),
+        Index(
+            "ix_mission_scenarios_active",
+            "deleted_at",
+            postgresql_where="deleted_at IS NULL",
+        ),
+    )
+
+
+class MissionTest(Base, UuidPkMixin, TimestampMixin, SoftDeleteMixin):
+    """Snapshot of a `test_template` + execution state + red/blue annotations."""
+
+    __tablename__ = "mission_tests"
+
+    scenario_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True),
+        ForeignKey("mission_scenarios.id", ondelete="CASCADE"),
+        nullable=False,
+    )
+    source_test_template_id: Mapped[uuid.UUID | None] = mapped_column(
+        Uuid(as_uuid=True),
+        ForeignKey("test_templates.id", ondelete="SET NULL"),
+        nullable=True,
+    )
+    position: Mapped[int] = mapped_column(Integer, nullable=False)
+
+    # --- Snapshot of the template (immutable after creation) ---
+    snapshot_name: Mapped[str] = mapped_column(String(255), nullable=False)
+    snapshot_description: Mapped[str | None] = mapped_column(Text, nullable=True)
+    snapshot_objective: Mapped[str | None] = mapped_column(Text, nullable=True)
+    snapshot_procedure_md: Mapped[str | None] = mapped_column(Text, nullable=True)
+    snapshot_prerequisites_md: Mapped[str | None] = mapped_column(Text, nullable=True)
+    snapshot_expected_red_md: Mapped[str | None] = mapped_column(Text, nullable=True)
+    snapshot_expected_blue_md: Mapped[str | None] = mapped_column(Text, nullable=True)
+    snapshot_opsec_level: Mapped[str] = mapped_column(
+        String(8), default="medium", nullable=False
+    )
+    snapshot_tags: Mapped[list[str]] = mapped_column(
+        ARRAY(String(64)), nullable=False, server_default="{}"
+    )
+    snapshot_expected_iocs: Mapped[list[str]] = mapped_column(
+        ARRAY(String(255)), nullable=False, server_default="{}"
+    )
+
+    # --- Execution state ---
+    state: Mapped[str] = mapped_column(String(24), default="pending", nullable=False)
+    executed_at: Mapped[datetime | None] = mapped_column(
+        DateTime(timezone=True), nullable=True
+    )
+    executed_at_overridden: Mapped[bool] = mapped_column(default=False, nullable=False)
+
+    # --- Red side (text-only per spec §4) ---
+    red_command: Mapped[str | None] = mapped_column(Text, nullable=True)
+    red_output: Mapped[str | None] = mapped_column(Text, nullable=True)
+    red_comment_md: Mapped[str | None] = mapped_column(Text, nullable=True)
+
+    # --- Blue side ---
+    blue_comment_md: Mapped[str | None] = mapped_column(Text, nullable=True)
+    detection_level_id: Mapped[uuid.UUID | None] = mapped_column(
+        Uuid(as_uuid=True),
+        ForeignKey("detection_levels.id", ondelete="SET NULL"),
+        nullable=True,
+    )
+    category_id: Mapped[uuid.UUID | None] = mapped_column(
+        Uuid(as_uuid=True),
+        ForeignKey("mission_categories.id", ondelete="SET NULL"),
+        nullable=True,
+    )
+
+    scenario: Mapped[MissionScenario] = relationship(back_populates="tests")
+    mitre_tags: Mapped[list["MissionTestMitreTag"]] = relationship(
+        back_populates="mission_test",
+        cascade="all, delete-orphan",
+        lazy="selectin",
+    )
+
+    __table_args__ = (
+        CheckConstraint(
+            f"snapshot_opsec_level IN ({', '.join(repr(v) for v in OPSEC_LEVELS)})",
+            name="snapshot_opsec_level_valid",
+        ),
+        CheckConstraint(
+            f"state IN ({', '.join(repr(v) for v in MISSION_TEST_STATES)})",
+            name="state_valid",
+        ),
+        UniqueConstraint("scenario_id", "position", name="uq_mission_tests_position"),
+        Index("ix_mission_tests_state", "state"),
+        Index(
+            "ix_mission_tests_active",
+            "deleted_at",
+            postgresql_where="deleted_at IS NULL",
+        ),
+    )
+
+
+class MissionCategory(Base, UuidPkMixin, TimestampMixin, SoftDeleteMixin):
+    """Optional custom grouping override for the slide synthesis."""
+
+    __tablename__ = "mission_categories"
+
+    mission_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True),
+        ForeignKey("missions.id", ondelete="CASCADE"),
+        nullable=False,
+    )
+    name: Mapped[str] = mapped_column(String(120), nullable=False)
+    color_token: Mapped[str | None] = mapped_column(String(16), nullable=True)
+    position: Mapped[int] = mapped_column(Integer, nullable=False)
+
+    mission: Mapped[Mission] = relationship(back_populates="categories")
+
+    __table_args__ = (
+        UniqueConstraint(
+            "mission_id", "position", name="uq_mission_categories_position"
+        ),
+        UniqueConstraint("mission_id", "name", name="uq_mission_categories_name"),
+        Index(
+            "ix_mission_categories_active",
+            "deleted_at",
+            postgresql_where="deleted_at IS NULL",
+        ),
+    )
+
+
+class MissionTestMitreTag(Base):
+    """Frozen MITRE tag attached to a mission test.
+
+    DELIBERATELY DENORMALISED — no FK to mitre_* tables. The MITRE
+    `external_id` and human label are copied at tag-creation time so that a
+    later MITRE re-sync that drops the original entry cannot purge or alter
+    a mission's tags. See spec §11 (snapshot vs reference).
+
+    The companion `test_template_mitre_tags` table keeps the FK relationship
+    because templates are editable and admins can re-tag them after a sync.
+    """
+
+    __tablename__ = "mission_test_mitre_tags"
+
+    id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True), primary_key=True, default=uuid.uuid4, nullable=False
+    )
+    mission_test_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True),
+        ForeignKey("mission_tests.id", ondelete="CASCADE"),
+        nullable=False,
+    )
+    mitre_kind: Mapped[str] = mapped_column(String(16), nullable=False)
+    mitre_external_id: Mapped[str] = mapped_column(String(16), nullable=False)
+    mitre_name: Mapped[str] = mapped_column(String(255), nullable=False)
+    mitre_url: Mapped[str | None] = mapped_column(String(512), nullable=True)
+
+    mission_test: Mapped[MissionTest] = relationship(back_populates="mitre_tags")
+
+    __table_args__: Any = (
+        CheckConstraint(
+            f"mitre_kind IN ({', '.join(repr(v) for v in MITRE_KINDS)})",
+            name="mitre_kind_valid",
+        ),
+        UniqueConstraint(
+            "mission_test_id",
+            "mitre_external_id",
+            name="uq_mission_test_mitre_tag",
+        ),
+        Index("ix_mission_test_mitre_tags_test", "mission_test_id"),
+    )
--- a/backend/app/models/mitre.py
+++ b/backend/app/models/mitre.py
@@ -0,0 +1,86 @@
+"""MITRE ATT&CK reference tables.
+
+Read-mostly. Hard delete (no soft-delete) — replaced by the periodic sync job.
+A technique can map to multiple tactics (kill_chain_phases in STIX) hence the
+M2M `technique_tactics` join. Sub-techniques inherit their parent's tactics
+through the parent technique.
+"""
+
+from __future__ import annotations
+
+import uuid
+
+from sqlalchemy import ForeignKey, Index, String, Text, Uuid
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.db.base import Base
+from app.db.mixins import TimestampMixin, UuidPkMixin
+
+
+class MitreTactic(Base, UuidPkMixin, TimestampMixin):
+    __tablename__ = "mitre_tactics"
+
+    external_id: Mapped[str] = mapped_column(String(16), unique=True, nullable=False)
+    short_name: Mapped[str] = mapped_column(String(80), nullable=False)
+    name: Mapped[str] = mapped_column(String(120), nullable=False)
+    description: Mapped[str | None] = mapped_column(Text, nullable=True)
+    url: Mapped[str | None] = mapped_column(String(512), nullable=True)
+
+    techniques: Mapped[list["MitreTechnique"]] = relationship(
+        secondary="mitre_technique_tactics",
+        back_populates="tactics",
+    )
+
+
+class MitreTechnique(Base, UuidPkMixin, TimestampMixin):
+    __tablename__ = "mitre_techniques"
+
+    external_id: Mapped[str] = mapped_column(String(16), unique=True, nullable=False)
+    name: Mapped[str] = mapped_column(String(255), nullable=False)
+    description: Mapped[str | None] = mapped_column(Text, nullable=True)
+    url: Mapped[str | None] = mapped_column(String(512), nullable=True)
+
+    tactics: Mapped[list[MitreTactic]] = relationship(
+        secondary="mitre_technique_tactics",
+        back_populates="techniques",
+        lazy="selectin",
+    )
+    subtechniques: Mapped[list["MitreSubtechnique"]] = relationship(
+        back_populates="technique",
+        cascade="all, delete-orphan",
+    )
+
+    __table_args__ = (Index("ix_mitre_techniques_name", "name"),)
+
+
+class MitreSubtechnique(Base, UuidPkMixin, TimestampMixin):
+    __tablename__ = "mitre_subtechniques"
+
+    external_id: Mapped[str] = mapped_column(String(16), unique=True, nullable=False)
+    name: Mapped[str] = mapped_column(String(255), nullable=False)
+    description: Mapped[str | None] = mapped_column(Text, nullable=True)
+    url: Mapped[str | None] = mapped_column(String(512), nullable=True)
+    technique_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True), ForeignKey("mitre_techniques.id", ondelete="CASCADE"), nullable=False
+    )
+
+    technique: Mapped[MitreTechnique] = relationship(back_populates="subtechniques")
+
+    __table_args__ = (Index("ix_mitre_subtechniques_technique_id", "technique_id"),)
+
+
+class MitreTechniqueTactic(Base):
+    """Many-to-many: a technique can serve several tactics (STIX kill_chain_phases)."""
+
+    __tablename__ = "mitre_technique_tactics"
+
+    technique_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True),
+        ForeignKey("mitre_techniques.id", ondelete="CASCADE"),
+        primary_key=True,
+    )
+    tactic_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True),
+        ForeignKey("mitre_tactics.id", ondelete="CASCADE"),
+        primary_key=True,
+    )
--- a/backend/app/models/notification.py
+++ b/backend/app/models/notification.py
@@ -0,0 +1,41 @@
+"""In-app notifications. Mail is out-of-scope for v1 (spec §4)."""
+
+from __future__ import annotations
+
+import uuid
+from datetime import datetime
+from typing import Any, TYPE_CHECKING
+
+from sqlalchemy import DateTime, ForeignKey, Index, String, Uuid
+from sqlalchemy.dialects.postgresql import JSONB
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.db.base import Base
+from app.db.mixins import TimestampMixin, UuidPkMixin
+
+if TYPE_CHECKING:
+    from app.models.auth import User
+
+
+class Notification(Base, UuidPkMixin, TimestampMixin):
+    __tablename__ = "notifications"
+
+    user_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True),
+        ForeignKey("users.id", ondelete="CASCADE"),
+        nullable=False,
+    )
+    type: Mapped[str] = mapped_column(String(64), nullable=False)
+    payload: Mapped[Any] = mapped_column(JSONB, nullable=False, server_default="{}")
+    read_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
+
+    user: Mapped["User"] = relationship(back_populates="notifications")
+
+    __table_args__ = (
+        Index(
+            "ix_notifications_user_unread",
+            "user_id",
+            "created_at",
+            postgresql_where="read_at IS NULL",
+        ),
+    )
--- a/backend/app/models/setting.py
+++ b/backend/app/models/setting.py
@@ -0,0 +1,37 @@
+"""Platform settings (key/value JSONB) and admin-defined detection levels."""
+
+from __future__ import annotations
+
+from typing import Any
+
+from sqlalchemy import Integer, String, Text
+from sqlalchemy.dialects.postgresql import JSONB
+from sqlalchemy.orm import Mapped, mapped_column
+
+from app.db.base import Base
+from app.db.mixins import TimestampMixin, UuidPkMixin
+
+
+class Setting(Base, TimestampMixin):
+    __tablename__ = "settings"
+
+    key: Mapped[str] = mapped_column(String(80), primary_key=True)
+    value: Mapped[Any] = mapped_column(JSONB, nullable=False)
+    description: Mapped[str | None] = mapped_column(Text, nullable=True)
+
+
+class DetectionLevel(Base, UuidPkMixin, TimestampMixin):
+    """Custom taxonomy admin can edit (cf. spec §F6).
+
+    Pre-seeded with detected_blocked / detected_alert / logged_only / not_detected.
+    """
+
+    __tablename__ = "detection_levels"
+
+    key: Mapped[str] = mapped_column(String(40), unique=True, nullable=False)
+    label_fr: Mapped[str] = mapped_column(String(80), nullable=False)
+    label_en: Mapped[str] = mapped_column(String(80), nullable=False)
+    color_token: Mapped[str] = mapped_column(String(16), nullable=False)
+    position: Mapped[int] = mapped_column(Integer, nullable=False)
+    is_default: Mapped[bool] = mapped_column(default=False, nullable=False)
+    is_system: Mapped[bool] = mapped_column(default=False, nullable=False)
--- a/backend/app/models/template.py
+++ b/backend/app/models/template.py
@@ -0,0 +1,174 @@
+"""Reusable templates: test_templates and scenario_templates.
+
+A `mission_scenarios` row is a snapshot copy of a `scenario_templates` row at
+mission-creation time. Templates can therefore be edited freely without
+disturbing already-running missions.
+"""
+
+from __future__ import annotations
+
+import uuid
+from typing import Any
+
+from sqlalchemy import (
+    ARRAY,
+    CheckConstraint,
+    ForeignKey,
+    Index,
+    Integer,
+    String,
+    Text,
+    UniqueConstraint,
+    Uuid,
+)
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.db.base import Base
+from app.db.mixins import SoftDeleteMixin, TimestampMixin, UuidPkMixin
+from app.db.types import MITRE_KINDS, OPSEC_LEVELS
+
+
+class TestTemplate(Base, UuidPkMixin, TimestampMixin, SoftDeleteMixin):
+    __tablename__ = "test_templates"
+
+    name: Mapped[str] = mapped_column(String(255), nullable=False)
+    description: Mapped[str | None] = mapped_column(Text, nullable=True)
+    objective: Mapped[str | None] = mapped_column(Text, nullable=True)
+    procedure_md: Mapped[str | None] = mapped_column(Text, nullable=True)
+    prerequisites_md: Mapped[str | None] = mapped_column(Text, nullable=True)
+    expected_result_red_md: Mapped[str | None] = mapped_column(Text, nullable=True)
+    expected_detection_blue_md: Mapped[str | None] = mapped_column(Text, nullable=True)
+    opsec_level: Mapped[str] = mapped_column(String(8), default="medium", nullable=False)
+    tags: Mapped[list[str]] = mapped_column(
+        ARRAY(String(64)), nullable=False, server_default="{}"
+    )
+    expected_iocs: Mapped[list[str]] = mapped_column(
+        ARRAY(String(255)), nullable=False, server_default="{}"
+    )
+
+    mitre_tags: Mapped[list["TestTemplateMitreTag"]] = relationship(
+        back_populates="test_template",
+        cascade="all, delete-orphan",
+        lazy="selectin",
+    )
+
+    __table_args__ = (
+        CheckConstraint(
+            f"opsec_level IN ({', '.join(repr(v) for v in OPSEC_LEVELS)})",
+            name="opsec_level_valid",
+        ),
+        Index("ix_test_templates_active", "deleted_at", postgresql_where="deleted_at IS NULL"),
+        Index("ix_test_templates_name", "name"),
+    )
+
+
+class TestTemplateMitreTag(Base):
+    """Polymorphic MITRE tag on a test template.
+
+    Exactly one of `tactic_id`, `technique_id`, `subtechnique_id` is set —
+    enforced by the CHECK constraint. This keeps FK integrity per MITRE level
+    while letting a single conceptual table answer "what's tagged on this test".
+    """
+
+    __tablename__ = "test_template_mitre_tags"
+
+    id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True), primary_key=True, default=uuid.uuid4, nullable=False
+    )
+    test_template_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True),
+        ForeignKey("test_templates.id", ondelete="CASCADE"),
+        nullable=False,
+    )
+    mitre_kind: Mapped[str] = mapped_column(String(16), nullable=False)
+    tactic_id: Mapped[uuid.UUID | None] = mapped_column(
+        Uuid(as_uuid=True), ForeignKey("mitre_tactics.id", ondelete="CASCADE"), nullable=True
+    )
+    technique_id: Mapped[uuid.UUID | None] = mapped_column(
+        Uuid(as_uuid=True), ForeignKey("mitre_techniques.id", ondelete="CASCADE"), nullable=True
+    )
+    subtechnique_id: Mapped[uuid.UUID | None] = mapped_column(
+        Uuid(as_uuid=True),
+        ForeignKey("mitre_subtechniques.id", ondelete="CASCADE"),
+        nullable=True,
+    )
+
+    test_template: Mapped[TestTemplate] = relationship(back_populates="mitre_tags")
+
+    __table_args__: Any = (
+        CheckConstraint(
+            f"mitre_kind IN ({', '.join(repr(v) for v in MITRE_KINDS)})",
+            name="mitre_kind_valid",
+        ),
+        CheckConstraint(
+            "(CASE WHEN tactic_id IS NOT NULL THEN 1 ELSE 0 END) "
+            "+ (CASE WHEN technique_id IS NOT NULL THEN 1 ELSE 0 END) "
+            "+ (CASE WHEN subtechnique_id IS NOT NULL THEN 1 ELSE 0 END) = 1",
+            name="exactly_one_mitre_fk",
+        ),
+        UniqueConstraint(
+            "test_template_id",
+            "tactic_id",
+            "technique_id",
+            "subtechnique_id",
+            name="uq_test_template_mitre_tag",
+        ),
+        Index("ix_test_template_mitre_tags_template", "test_template_id"),
+    )
+
+
+class ScenarioTemplate(Base, UuidPkMixin, TimestampMixin, SoftDeleteMixin):
+    __tablename__ = "scenario_templates"
+
+    name: Mapped[str] = mapped_column(String(255), nullable=False)
+    description: Mapped[str | None] = mapped_column(Text, nullable=True)
+
+    tests: Mapped[list["ScenarioTemplateTest"]] = relationship(
+        back_populates="scenario_template",
+        cascade="all, delete-orphan",
+        order_by="ScenarioTemplateTest.position",
+    )
+
+    __table_args__ = (
+        Index(
+            "ix_scenario_templates_active",
+            "deleted_at",
+            postgresql_where="deleted_at IS NULL",
+        ),
+        Index("ix_scenario_templates_name", "name"),
+    )
+
+
+class ScenarioTemplateTest(Base, UuidPkMixin):
+    """Ordered membership of a test template inside a scenario template.
+
+    UUID PK + UNIQUE(scenario_template_id, position) lets the same test appear
+    multiple times at different positions (chained operations are common in
+    purple-team scenarios).
+    """
+
+    __tablename__ = "scenario_template_tests"
+
+    scenario_template_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True),
+        ForeignKey("scenario_templates.id", ondelete="CASCADE"),
+        nullable=False,
+    )
+    test_template_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True),
+        ForeignKey("test_templates.id", ondelete="RESTRICT"),
+        nullable=False,
+    )
+    position: Mapped[int] = mapped_column(Integer, nullable=False)
+
+    scenario_template: Mapped[ScenarioTemplate] = relationship(back_populates="tests")
+
+    __table_args__ = (
+        UniqueConstraint(
+            "scenario_template_id",
+            "position",
+            name="uq_scenario_template_tests_position",
+        ),
+        Index("ix_scenario_template_tests_scenario", "scenario_template_id"),
+        Index("ix_scenario_template_tests_test", "test_template_id"),
+    )