chore(backend): bootstrap Python 3.12+ project skeleton (B0.1)

- pyproject.toml with ruff + mypy strict + pytest + coverage >=70%
- Makefile with Docker/Podman auto-detect
- Multi-stage Dockerfile (python:3.12-slim-bookworm, non-root user)
- docker-compose.yml for Postgres dev DB
- alembic.ini wired to src/mimic/db/migrations
- scripts/postgres-init/00-roles.sql seeds the audit writer role
- .env.example documents every MIMIC_* var (no secrets committed)

backend/Makefile

@@ -0,0 +1,80 @@
+# --- Mimic backend Makefile ------------------------------------------------
+# Detects Docker / Podman automatically (NF-platform).
+
+PY        ?= python3.12
+VENV      ?= .venv
+PIP       := $(VENV)/bin/pip
+PYTHON    := $(VENV)/bin/python
+PYTEST    := $(VENV)/bin/pytest
+RUFF      := $(VENV)/bin/ruff
+MYPY      := $(VENV)/bin/mypy
+ALEMBIC   := $(VENV)/bin/alembic
+FLASK     := $(VENV)/bin/flask
+
+# Container runtime auto-detect: Docker (preferred) or Podman rootless.
+CONTAINER ?= $(shell command -v docker 2>/dev/null || command -v podman 2>/dev/null)
+COMPOSE   ?= $(shell command -v docker-compose 2>/dev/null || echo "$(CONTAINER) compose")
+
+export FLASK_APP=mimic.app:create_app
+
+.PHONY: help install lint fmt typecheck test test-int test-cov run \
+        db-up db-down db-migrate db-revision db-seed db-dump db-restore \
+        build clean
+
+help:
+	@grep -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | sort | \
+	  awk 'BEGIN {FS=":.*?## "}; {printf "  \033[36m%-20s\033[0m %s\n", $$1, $$2}'
+
+install: ## Create venv and install dev dependencies
+	$(PY) -m venv $(VENV)
+	$(PIP) install --upgrade pip wheel
+	$(PIP) install -e ".[dev]"
+
+lint: ## Ruff lint
+	$(RUFF) check src tests
+
+fmt: ## Ruff format
+	$(RUFF) format src tests
+	$(RUFF) check --fix src tests
+
+typecheck: ## Mypy strict
+	$(MYPY) src
+
+test: ## Unit tests (SQLite)
+	$(PYTEST) tests/unit -v
+
+test-int: ## Integration tests (testcontainers Postgres)
+	$(PYTEST) tests/integration -v -m integration
+
+test-cov: ## Unit + integration with coverage report
+	$(PYTEST) --cov=mimic --cov-report=term-missing --cov-report=html
+
+run: ## Run Flask dev server
+	$(FLASK) run --host 0.0.0.0 --port 5000 --debug
+
+db-up: ## Start Postgres dev container
+	$(COMPOSE) up -d postgres
+
+db-down: ## Stop Postgres dev container
+	$(COMPOSE) down
+
+db-migrate: ## Apply migrations
+	$(ALEMBIC) upgrade head
+
+db-revision: ## Generate migration (msg=...)
+	$(ALEMBIC) revision --autogenerate -m "$(msg)"
+
+db-seed: ## Seed local dev data (TBD sprint 1)
+	@echo "TBD sprint 1"
+
+db-dump: ## Manual DB dump (NF-state, R-O1)
+	$(VENV)/bin/mimic-cli db dump --out backups/mimic-$$(date +%Y%m%d-%H%M%S).sql
+
+db-restore: ## Restore from dump (file=...)
+	$(VENV)/bin/mimic-cli db restore --file $(file)
+
+build: ## Build wheel
+	$(PYTHON) -m build
+
+clean:
+	rm -rf $(VENV) .pytest_cache .mypy_cache .ruff_cache htmlcov dist build *.egg-info