Add standalone FastAPI server backend (Phase 3)

Build a complete standalone web server for Immich album change
notifications, independent of Home Assistant. Uses the shared
core library from Phase 1.

Server features:
- FastAPI with async SQLite (SQLModel + aiosqlite)
- Multi-user auth with JWT (admin/user roles, setup wizard)
- CRUD APIs: Immich servers, album trackers, message templates,
  notification targets (Telegram + webhook), user management
- APScheduler background polling per tracker
- Jinja2 template rendering with live preview
- Album browser proxied from Immich API
- Event logging and dashboard status endpoint
- Docker deployment (single container, SQLite in volume)

39 API routes, 14 integration tests passing.

Also adds Phase 6 (Claude AI Telegram bot enhancement) to the
primary plan as an optional future phase.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/server/src/immich_watcher_server/api/servers.py

@@ -0,0 +1,158 @@
+"""Immich server management API routes."""
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from pydantic import BaseModel
+from sqlmodel import select
+from sqlmodel.ext.asyncio.session import AsyncSession
+
+import aiohttp
+
+from immich_watcher_core.immich_client import ImmichClient
+
+from ..auth.dependencies import get_current_user
+from ..database.engine import get_session
+from ..database.models import ImmichServer, User
+
+router = APIRouter(prefix="/api/servers", tags=["servers"])
+
+
+class ServerCreate(BaseModel):
+    name: str = "Immich"
+    url: str
+    api_key: str
+
+
+class ServerUpdate(BaseModel):
+    name: str | None = None
+    url: str | None = None
+    api_key: str | None = None
+
+
+class ServerResponse(BaseModel):
+    id: int
+    name: str
+    url: str
+    created_at: str
+
+
+@router.get("")
+async def list_servers(
+    user: User = Depends(get_current_user),
+    session: AsyncSession = Depends(get_session),
+):
+    """List all Immich servers for the current user."""
+    result = await session.exec(
+        select(ImmichServer).where(ImmichServer.user_id == user.id)
+    )
+    servers = result.all()
+    return [
+        {"id": s.id, "name": s.name, "url": s.url, "created_at": s.created_at.isoformat()}
+        for s in servers
+    ]
+
+
+@router.post("", status_code=status.HTTP_201_CREATED)
+async def create_server(
+    body: ServerCreate,
+    user: User = Depends(get_current_user),
+    session: AsyncSession = Depends(get_session),
+):
+    """Add a new Immich server (validates connection)."""
+    # Validate connection
+    async with aiohttp.ClientSession() as http_session:
+        client = ImmichClient(http_session, body.url, body.api_key)
+        if not await client.ping():
+            raise HTTPException(
+                status_code=status.HTTP_400_BAD_REQUEST,
+                detail=f"Cannot connect to Immich server at {body.url}",
+            )
+        # Fetch external domain
+        external_domain = await client.get_server_config()
+
+    server = ImmichServer(
+        user_id=user.id,
+        name=body.name,
+        url=body.url,
+        api_key=body.api_key,
+        external_domain=external_domain,
+    )
+    session.add(server)
+    await session.commit()
+    await session.refresh(server)
+    return {"id": server.id, "name": server.name, "url": server.url}
+
+
+@router.get("/{server_id}")
+async def get_server(
+    server_id: int,
+    user: User = Depends(get_current_user),
+    session: AsyncSession = Depends(get_session),
+):
+    """Get a specific Immich server."""
+    server = await _get_user_server(session, server_id, user.id)
+    return {"id": server.id, "name": server.name, "url": server.url, "created_at": server.created_at.isoformat()}
+
+
+@router.put("/{server_id}")
+async def update_server(
+    server_id: int,
+    body: ServerUpdate,
+    user: User = Depends(get_current_user),
+    session: AsyncSession = Depends(get_session),
+):
+    """Update an Immich server."""
+    server = await _get_user_server(session, server_id, user.id)
+    if body.name is not None:
+        server.name = body.name
+    if body.url is not None:
+        server.url = body.url
+    if body.api_key is not None:
+        server.api_key = body.api_key
+    session.add(server)
+    await session.commit()
+    await session.refresh(server)
+    return {"id": server.id, "name": server.name, "url": server.url}
+
+
+@router.delete("/{server_id}", status_code=status.HTTP_204_NO_CONTENT)
+async def delete_server(
+    server_id: int,
+    user: User = Depends(get_current_user),
+    session: AsyncSession = Depends(get_session),
+):
+    """Delete an Immich server."""
+    server = await _get_user_server(session, server_id, user.id)
+    await session.delete(server)
+    await session.commit()
+
+
+@router.get("/{server_id}/albums")
+async def list_albums(
+    server_id: int,
+    user: User = Depends(get_current_user),
+    session: AsyncSession = Depends(get_session),
+):
+    """Fetch albums from an Immich server."""
+    server = await _get_user_server(session, server_id, user.id)
+    async with aiohttp.ClientSession() as http_session:
+        client = ImmichClient(http_session, server.url, server.api_key)
+        albums = await client.get_albums()
+    return [
+        {
+            "id": a.get("id"),
+            "albumName": a.get("albumName"),
+            "assetCount": a.get("assetCount", 0),
+            "shared": a.get("shared", False),
+        }
+        for a in albums
+    ]
+
+
+async def _get_user_server(
+    session: AsyncSession, server_id: int, user_id: int
+) -> ImmichServer:
+    """Get a server owned by the user, or raise 404."""
+    server = await session.get(ImmichServer, server_id)
+    if not server or server.user_id != user_id:
+        raise HTTPException(status_code=404, detail="Server not found")
+    return server