Scaffold FastAPI + MySQL + Keycloak service with devcontainer

Sets up the project skeleton:

- FastAPI app factory with lifespan, request-id middleware, and RFC 9457
  problem+json error handlers
- Async SQLAlchemy 2.0 over MySQL (asyncmy), with a constraint naming
  convention in place before the first migration and async Alembic
- Keycloak as a pure resource server: OIDC discovery, cached JWKS with
  rotation-aware refresh, and require_roles dependencies
- Devcontainer running MySQL 8.4 and Keycloak 26.7 as compose siblings,
  with the realm (clients, roles, test users) imported on first boot
- Test suite covering the endpoints plus the token validator itself,
  exercised against a locally generated RSA keypair
- uv packaging, ruff, mypy --strict, pre-commit, Gitea CI, prod Dockerfile

Two Keycloak-in-containers traps are handled explicitly and documented in
the README: the issuer/internal-URL split (the browser sees localhost:8080,
the API sees keycloak:8080) and the audience mapper that stops Keycloak
issuing tokens with aud=account.

The devices resource is a placeholder proving the routing -> auth -> ORM ->
migration path end to end; replace it with the real domain.

Co-Authored-By: Claude Opus 5 <[email protected]>

migrations/versions/367021e73a20_create_devices_table.py

@@ -0,0 +1,65 @@
+"""create devices table
+
+Revision ID: 367021e73a20
+Revises:
+Create Date: 2026-09-10
+
+"""
+
+from collections.abc import Sequence
+
+import sqlalchemy as sa
+from alembic import op
+
+revision: str = "367021e73a20"
+down_revision: str | None = None
+branch_labels: str | Sequence[str] | None = None
+depends_on: str | Sequence[str] | None = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "devices",
+        sa.Column("id", sa.Integer(), autoincrement=True, nullable=False),
+        sa.Column("name", sa.String(length=128), nullable=False),
+        sa.Column("serial", sa.String(length=64), nullable=False),
+        sa.Column(
+            "status",
+            sa.Enum(
+                "active",
+                "inactive",
+                "maintenance",
+                name="devicestatus",
+                native_enum=False,
+                length=32,
+            ),
+            server_default="active",
+            nullable=False,
+        ),
+        sa.Column("description", sa.String(length=512), nullable=True),
+        # Plain CURRENT_TIMESTAMP rather than the parenthesised form autogenerate
+        # emits under SQLite: this spelling is valid on both backends.
+        sa.Column(
+            "created_at",
+            sa.DateTime(timezone=True),
+            server_default=sa.text("CURRENT_TIMESTAMP"),
+            nullable=False,
+        ),
+        sa.Column(
+            "updated_at",
+            sa.DateTime(timezone=True),
+            server_default=sa.text("CURRENT_TIMESTAMP"),
+            nullable=False,
+        ),
+        sa.PrimaryKeyConstraint("id", name=op.f("pk_devices")),
+        sa.UniqueConstraint("serial", name=op.f("uq_devices_serial")),
+        mysql_engine="InnoDB",
+        mysql_charset="utf8mb4",
+        mysql_collate="utf8mb4_0900_ai_ci",
+    )
+    op.create_index(op.f("ix_devices_name"), "devices", ["name"], unique=False)
+
+
+def downgrade() -> None:
+    op.drop_index(op.f("ix_devices_name"), table_name="devices")
+    op.drop_table("devices")