Phase 0: repo skeleton, image, compose stacks, doctor, migration runner, frontend shell

New repo for the Packet Station rebuild (Python 3.12, FastAPI, PostgreSQL 16,
React, VisualKit, MFilesKit, Docker Compose on docker-1). Nothing is migrated
from the M: install.

- CLAUDE.md with the safety rules, README, CHANGELOG, docs (BRIEF, PLAN,
  SECURITY rewritten for the server with the requirement ID table, DEPLOY,
  stubs for FEED, POLICY, SCHEMA, GO-LIVE, PAPER-FALLBACK).
- packetstation CLI: app, worker (heartbeat stub), migrate, doctor, version,
  healthcheck. Settings from the environment with secret files. Stack guard
  (test never points at VISUAL production). Security headers and CSP.
  Trusted proxy resolved by name. JSON logs with redaction.
- Migration runner and 0001_base: settings, append-only audit_events with
  hash chain, ps_notify, grants for ps_app.
- Multi-stage Dockerfile (ODBC Driver 18, PESCO libraries from the Gitea
  index only), compose base, proxy overlay for npm_default, CI overlay,
  postgres initdb roles, env examples, NPM proxy host notes, Gitea Actions.
- Frontend: Vite, React, TypeScript, the PESCO dark theme ported with
  self-hosted fonts, placeholder sign-in and home.
- Verified on docker-1: image builds, CI stack comes up healthy, doctor
  database checks pass, 77 server tests pass against PostgreSQL.

Co-Authored-By: Claude Fable 5.1 <[email protected]>

server/packetstation/db.py

@@ -0,0 +1,83 @@
+"""PostgreSQL access: one pool for the app role, plain connections for other roles."""
+
+from __future__ import annotations
+
+import logging
+import threading
+from pathlib import Path
+from typing import Any, Literal
+
+import psycopg
+from psycopg_pool import ConnectionPool
+
+from .settings import Settings, get_settings
+
+log = logging.getLogger(__name__)
+
+Role = Literal["app", "worker", "migrate"]
+MIGRATIONS_DIR = Path(__file__).resolve().parent / "migrations"
+APP_NAMES: dict[str, str] = {"app": "ps-app", "worker": "ps-worker", "migrate": "ps-migrate"}
+
+
+class DatabaseUnavailable(Exception):
+    """No connection could be made (bad secret, server down, pool timeout)."""
+
+
+def connect_kwargs(role: Role, settings: Settings | None = None) -> dict[str, Any]:
+    """Connection keyword arguments for a role. The worker logs in as the app user."""
+    s = settings or get_settings()
+    db_role = "migrate" if role == "migrate" else "app"
+    return {
+        "host": s.pg_host,
+        "port": s.pg_port,
+        "dbname": s.pg_database,
+        "user": s.pg_user(db_role),
+        "password": s.pg_password(db_role),
+        "application_name": APP_NAMES[role],
+        "connect_timeout": 5,
+    }
+
+
+def connect_as(role: Role, settings: Settings | None = None, **extra: Any) -> psycopg.Connection[Any]:
+    """A new connection as the given role; the caller closes it."""
+    kwargs = connect_kwargs(role, settings)
+    kwargs.update(extra)
+    return psycopg.connect(**kwargs)
+
+
+_pool: ConnectionPool[Any] | None = None
+_pool_lock = threading.Lock()
+
+
+def get_pool(settings: Settings | None = None) -> ConnectionPool[Any]:
+    """The app role's pool, opened on first use without waiting for the server."""
+    global _pool
+    with _pool_lock:
+        if _pool is None:
+            try:
+                kwargs = connect_kwargs("app", settings)
+            except Exception as e:
+                raise DatabaseUnavailable(str(e)) from None
+            _pool = ConnectionPool(kwargs=kwargs, min_size=1, max_size=10, open=False, name="ps-app")
+            _pool.open(wait=False)
+        return _pool
+
+
+def close_pool() -> None:
+    global _pool
+    with _pool_lock:
+        if _pool is not None:
+            _pool.close()
+            _pool = None
+
+
+def ping(settings: Settings | None = None, timeout: float = 3.0) -> None:
+    """SELECT 1 as the app role; raises DatabaseUnavailable."""
+    try:
+        pool = get_pool(settings)
+        with pool.connection(timeout=timeout) as conn:
+            conn.execute("SELECT 1").fetchone()
+    except DatabaseUnavailable:
+        raise
+    except Exception as e:
+        raise DatabaseUnavailable(type(e).__name__) from None