Initial commit: StackPilot Phase 1 (Core)

Self-hosted Docker Compose manager.
- Backend: FastAPI + docker-py + SQLite (JWT auth, file-first stacks,
  lifecycle, live status, WebSocket logs, docker-run converter, audit log)
- Frontend: React + Vite + Tailwind (login/setup, dashboard, stacks,
  stack detail, Monaco editor, dark/light theme)
- Deployment: docker-compose.yml, Dockerfiles, nginx reverse proxy

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/main.py

@@ -0,0 +1,62 @@
+"""StackPilot backend — FastAPI application entry point."""
+from __future__ import annotations
+
+import logging
+from contextlib import asynccontextmanager
+
+from fastapi import FastAPI, Request
+from fastapi.middleware.cors import CORSMiddleware
+from fastapi.responses import JSONResponse
+from sqlmodel import Session
+
+from config import settings
+from database import engine, init_db
+from docker_client import DockerError
+from routers import audit, auth, stacks, system, ws
+
+logging.basicConfig(level=logging.INFO)
+logger = logging.getLogger("stackpilot")
+
+
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    init_db()
+    # Register stacks that already exist on disk.
+    try:
+        with Session(engine) as session:
+            stacks.sync_discovered_stacks(session)
+    except Exception as exc:  # noqa: BLE001
+        logger.warning("Stack discovery failed: %s", exc)
+    logger.info("StackPilot backend ready on port %s", settings.PORT)
+    yield
+
+
+app = FastAPI(title="StackPilot", version="0.1.0", lifespan=lifespan)
+
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=settings.CORS_ORIGINS,
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+
+@app.exception_handler(DockerError)
+async def docker_error_handler(_request: Request, exc: DockerError):
+    return JSONResponse(
+        status_code=502,
+        content={"error": exc.error, "detail": exc.detail},
+    )
+
+
+app.include_router(auth.router)
+app.include_router(stacks.router)
+app.include_router(system.router)
+app.include_router(audit.router)
+app.include_router(ws.router)
+
+
+@app.get("/api/health")
+def health() -> dict:
+    return {"status": "ok"}