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/proxy.py

@@ -0,0 +1,110 @@
+"""Trust X-Forwarded-For / X-Forwarded-Proto only from the proxy's resolved addresses."""
+
+from __future__ import annotations
+
+import asyncio
+import ipaddress
+import logging
+import socket
+from collections.abc import Callable, Iterable
+
+from starlette.requests import Request
+from starlette.types import ASGIApp, Receive, Scope, Send
+
+log = logging.getLogger(__name__)
+
+REFRESH_SECONDS = 60
+
+
+def _ip(text: str) -> str | None:
+    try:
+        return str(ipaddress.ip_address(text.strip()))
+    except ValueError:
+        return None
+
+
+def resolve_host(host: str) -> set[str]:
+    """Every address the name resolves to (IPv4 and IPv6)."""
+    infos = socket.getaddrinfo(host, None, proto=socket.IPPROTO_TCP)
+    out = {ip for info in infos if (ip := _ip(str(info[4][0]).split("%")[0]))}
+    return out
+
+
+class TrustedProxies:
+    """The current set of trusted peer addresses. A failed refresh keeps the last good set."""
+
+    def __init__(self, host: str, resolver: Callable[[str], set[str]] = resolve_host):
+        self.host = host.strip()
+        self.addresses: frozenset[str] = frozenset()
+        self._resolver = resolver
+
+    def refresh(self) -> None:
+        if not self.host:
+            return
+        try:
+            found = self._resolver(self.host)
+        except OSError as e:
+            log.warning(
+                "can't resolve TRUSTED_PROXY_HOST %s (%s); keeping %s",
+                self.host,
+                e,
+                sorted(self.addresses) or "nothing",
+            )
+            return
+        if found != self.addresses:
+            log.info("trusted proxy %s is %s", self.host, sorted(found))
+        self.addresses = frozenset(found)
+
+    def trusts(self, peer: str | None) -> bool:
+        return bool(peer) and _ip(peer or "") in self.addresses
+
+    async def run(self) -> None:
+        """Background loop: re-resolve every 60 s."""
+        while True:
+            await asyncio.sleep(REFRESH_SECONDS)
+            await asyncio.to_thread(self.refresh)
+
+
+def forwarded(
+    peer: str | None, headers: Iterable[tuple[bytes, bytes]], trusted: TrustedProxies
+) -> tuple[str | None, str | None]:
+    """(client ip, scheme) to use; (peer, None) when the peer is not trusted or headers are unusable."""
+    if not trusted.trusts(peer):
+        return peer, None
+    xff = proto = None
+    for k, v in headers:
+        name = k.lower()
+        if name == b"x-forwarded-for" and xff is None:
+            xff = v.decode("latin-1")
+        elif name == b"x-forwarded-proto" and proto is None:
+            proto = v.decode("latin-1").split(",")[0].strip().lower()
+    client = peer
+    if xff:
+        first = _ip(xff.split(",")[0])
+        if first:
+            client = first
+    scheme = proto if proto in ("http", "https") else None
+    return client, scheme
+
+
+class TrustedProxyMiddleware:
+    def __init__(self, app: ASGIApp, trusted: TrustedProxies):
+        self.app = app
+        self.trusted = trusted
+
+    async def __call__(self, scope: Scope, receive: Receive, send: Send) -> None:
+        if scope["type"] in ("http", "websocket"):
+            client = scope.get("client")
+            peer = client[0] if client else None
+            ip, scheme = forwarded(peer, scope.get("headers", []), self.trusted)
+            if ip != peer or scheme:
+                scope = dict(scope)
+                scope["client"] = (ip, client[1] if client else 0)
+                if scheme:
+                    scope["scheme"] = scheme if scope["type"] == "http" else ("wss" if scheme == "https" else "ws")
+        await self.app(scope, receive, send)
+
+
+def client_ip(request: Request) -> str | None:
+    """The real client address (after trusted-proxy handling)."""
+    return request.client.host if request.client else None