Phase1 skeleton: replace demo main.py with src.server contract

- Overlay ModelHub XC Phase1 (health/status, STRATEGY_ID gate, dry-run)
- Dockerfile CMD -> python -m src.server; FROM stays platform TCR base
- Remove demo main.py and requirements.txt (stdlib only)
- Add tests/, scripts/, docs/, Makefile, config/examples (no secrets)

src/server.py

@@ -0,0 +1,83 @@
+"""Minimal HTTP server for the adaptation agent (stdlib only).
+
+Listens on PORT (default 8080). Handles SIGTERM and exits the main loop
+within ~1s (platform window documented as ≤30s).
+
+Startup: require STRATEGY_ID (Phase1 product plan — fail if missing).
+"""
+
+from __future__ import annotations
+
+import os
+import signal
+import sys
+import threading
+from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer
+from typing import Optional
+
+from .health import handle_get
+from .strategy import require_strategy_id
+
+_shutdown = threading.Event()
+_httpd: Optional[ThreadingHTTPServer] = None
+
+
+class AgentHandler(BaseHTTPRequestHandler):
+    protocol_version = "HTTP/1.1"
+
+    def log_message(self, fmt: str, *args) -> None:  # noqa: A003
+        # Avoid noisy default logging; never log env secrets.
+        sys.stderr.write("[http] request handled (details omitted)\n")
+
+    def do_GET(self) -> None:  # noqa: N802
+        code, headers, body = handle_get(self.path)
+        self.send_response(code)
+        for k, v in headers.items():
+            self.send_header(k, v)
+        self.send_header("Content-Length", str(len(body)))
+        self.end_headers()
+        self.wfile.write(body)
+
+    def do_POST(self) -> None:  # noqa: N802
+        body = b'{"error":"method_not_allowed"}'
+        self.send_response(405)
+        self.send_header("Content-Type", "application/json; charset=utf-8")
+        self.send_header("Content-Length", str(len(body)))
+        self.end_headers()
+        self.wfile.write(body)
+
+
+def _on_sigterm(signum: int, frame) -> None:  # noqa: ARG001
+    sys.stderr.write(f"Received signal {signum}; shutting down...\n")
+    _shutdown.set()
+    httpd = _httpd
+    if httpd is not None:
+        # wake serve_forever
+        threading.Thread(target=httpd.shutdown, daemon=True).start()
+
+
+def main() -> None:
+    global _httpd
+
+    require_strategy_id()  # exit 1 if missing
+
+    port = int(os.environ.get("PORT", "8080"))
+    host = os.environ.get("HOST", "0.0.0.0")
+
+    signal.signal(signal.SIGTERM, _on_sigterm)
+    signal.signal(signal.SIGINT, _on_sigterm)
+
+    httpd = ThreadingHTTPServer((host, port), AgentHandler)
+    httpd.daemon_threads = True
+    _httpd = httpd
+
+    sys.stderr.write(f"Listening on {host}:{port} (GET /health, GET /status)\n")
+    try:
+        httpd.serve_forever(poll_interval=0.5)
+    finally:
+        httpd.server_close()
+        sys.stderr.write("Server stopped.\n")
+
+
+if __name__ == "__main__":
+    main()