Refactor gateway into modular architecture

Split 1878-line server.py into 15 focused modules:
- config.py: all env vars and constants
- database.py: schema, init, seed logic
- sessions.py: session/token CRUD
- proxy.py: proxy_request, SERVICE_MAP, resolve_service
- responses.py: ResponseMixin for handler helpers
- auth.py: login/logout/register handlers
- dashboard.py: dashboard, apps, connections, pinning
- command.py: AI command bar
- integrations/booklore.py: auth, books, cover, import
- integrations/kindle.py: send-to-kindle, file finder
- integrations/karakeep.py: save/delete bookmarks
- integrations/qbittorrent.py: download status
- integrations/image_proxy.py: external image proxy

server.py is now thin routing only (~344 lines).
All routes, methods, status codes, and responses preserved exactly.
Added PYTHONUNBUFFERED=1 to Dockerfile for live logging.

gateway/database.py

@@ -0,0 +1,133 @@
+"""
+Platform Gateway — Database initialization and access.
+"""
+
+import hashlib
+import sqlite3
+
+from config import (
+    DB_PATH, TRIPS_URL, FITNESS_URL, INVENTORY_URL,
+    MINIFLUX_URL, SHELFMARK_URL, SPOTIZERR_URL, BUDGET_URL,
+)
+
+
+def get_db():
+    conn = sqlite3.connect(str(DB_PATH))
+    conn.row_factory = sqlite3.Row
+    conn.execute("PRAGMA foreign_keys = ON")
+    conn.execute("PRAGMA journal_mode = WAL")
+    return conn
+
+
+def init_db():
+    conn = get_db()
+    c = conn.cursor()
+
+    c.execute('''CREATE TABLE IF NOT EXISTS users (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        username TEXT UNIQUE NOT NULL,
+        password_hash TEXT NOT NULL,
+        display_name TEXT NOT NULL DEFAULT '',
+        created_at TEXT DEFAULT CURRENT_TIMESTAMP
+    )''')
+
+    c.execute('''CREATE TABLE IF NOT EXISTS sessions (
+        token TEXT PRIMARY KEY,
+        user_id INTEGER NOT NULL,
+        created_at TEXT DEFAULT CURRENT_TIMESTAMP,
+        expires_at TEXT NOT NULL,
+        FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
+    )''')
+
+    c.execute('''CREATE TABLE IF NOT EXISTS service_connections (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        user_id INTEGER NOT NULL,
+        service TEXT NOT NULL,
+        auth_type TEXT NOT NULL DEFAULT 'bearer',
+        auth_token TEXT NOT NULL,
+        metadata TEXT DEFAULT '{}',
+        created_at TEXT DEFAULT CURRENT_TIMESTAMP,
+        UNIQUE(user_id, service),
+        FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
+    )''')
+
+    c.execute('''CREATE TABLE IF NOT EXISTS apps (
+        id TEXT PRIMARY KEY,
+        name TEXT NOT NULL,
+        icon TEXT DEFAULT '',
+        route_prefix TEXT NOT NULL,
+        proxy_target TEXT NOT NULL,
+        sort_order INTEGER DEFAULT 0,
+        enabled INTEGER DEFAULT 1,
+        dashboard_widget TEXT DEFAULT NULL
+    )''')
+
+    c.execute('''CREATE TABLE IF NOT EXISTS pinned_items (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        user_id INTEGER NOT NULL,
+        service TEXT NOT NULL DEFAULT 'inventory',
+        item_id TEXT NOT NULL,
+        item_name TEXT NOT NULL DEFAULT '',
+        pinned_at TEXT DEFAULT CURRENT_TIMESTAMP,
+        UNIQUE(user_id, service, item_id),
+        FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
+    )''')
+
+    conn.commit()
+
+    # Seed default apps
+    existing = c.execute("SELECT COUNT(*) FROM apps").fetchone()[0]
+    if existing == 0:
+        c.execute("INSERT INTO apps VALUES ('trips', 'Trips', 'map', '/trips', ?, 1, 1, 'upcoming_trips')", (TRIPS_URL,))
+        c.execute("INSERT INTO apps VALUES ('fitness', 'Fitness', 'bar-chart', '/fitness', ?, 2, 1, 'daily_calories')", (FITNESS_URL,))
+        c.execute("INSERT INTO apps VALUES ('inventory', 'Inventory', 'package', '/inventory', ?, 3, 1, 'items_issues')", (INVENTORY_URL,))
+        conn.commit()
+    else:
+        # Ensure inventory app exists (migration for existing DBs)
+        inv = c.execute("SELECT id FROM apps WHERE id = 'inventory'").fetchone()
+        if not inv:
+            c.execute("INSERT INTO apps VALUES ('inventory', 'Inventory', 'package', '/inventory', ?, 3, 1, 'items_issues')", (INVENTORY_URL,))
+            conn.commit()
+            print("[Gateway] Added inventory app")
+
+    # Ensure reader app exists
+    rdr = c.execute("SELECT id FROM apps WHERE id = 'reader'").fetchone()
+    if not rdr:
+        c.execute("INSERT INTO apps VALUES ('reader', 'Reader', 'rss', '/reader', ?, 4, 1, 'unread_count')", (MINIFLUX_URL,))
+        conn.commit()
+        print("[Gateway] Added reader app")
+
+    # Ensure books app exists (now media)
+    books = c.execute("SELECT id FROM apps WHERE id = 'books'").fetchone()
+    if not books:
+        c.execute("INSERT INTO apps VALUES ('books', 'Media', 'book', '/media', ?, 5, 1, NULL)", (SHELFMARK_URL,))
+        conn.commit()
+        print("[Gateway] Added media app")
+    else:
+        c.execute("UPDATE apps SET name = 'Media', route_prefix = '/media' WHERE id = 'books'")
+        conn.commit()
+
+    # Ensure music (spotizerr) app exists
+    music = c.execute("SELECT id FROM apps WHERE id = 'music'").fetchone()
+    if not music:
+        c.execute("INSERT INTO apps VALUES ('music', 'Music', 'music', '/music', ?, 6, 1, NULL)", (SPOTIZERR_URL,))
+        conn.commit()
+        print("[Gateway] Added music app")
+
+    # Ensure budget app exists
+    budget = c.execute("SELECT id FROM apps WHERE id = 'budget'").fetchone()
+    if not budget:
+        c.execute("INSERT OR IGNORE INTO apps VALUES ('budget', 'Budget', 'dollar-sign', '/budget', ?, 7, 1, 'budget_summary')", (BUDGET_URL,))
+        conn.commit()
+        print("[Gateway] Added budget app")
+
+    # Seed default admin user if empty
+    user_count = c.execute("SELECT COUNT(*) FROM users").fetchone()[0]
+    if user_count == 0:
+        pw_hash = hashlib.sha256("admin".encode()).hexdigest()
+        c.execute("INSERT INTO users (username, password_hash, display_name) VALUES (?, ?, ?)",
+                  ("admin", pw_hash, "Yusuf"))
+        conn.commit()
+        print("[Gateway] Created default user: admin / admin")
+
+    conn.close()