Complete LinkSyncServer and LinkSyncExtension implementation

LinkSyncServer:
- Fix app.py imports, add CORS middleware, lifespan events
- Create api/routes.py router aggregator
- Create config/settings.py for centralized configuration
- Rewrite models/base.py with proper relationships and serialization
- Rewrite all API endpoints with real DB integration (auth, links, collections, sync, queries, tags)
- Add admin endpoints (user management, stats, audit log)
- Complete query parser with recursive descent and proper precedence
- Complete query executor with set operations and field filters
- Set up Alembic migrations with initial schema
- Create web interface (templates, CSS, JS)
- Add 42 passing tests (auth, links, collections, queries)
- Add deploy.ps1 and deploy.sh scripts
- Update README with deployment workflow

LinkSyncExtension:
- Create utils/api.js (REST client with retries, auth, error handling)
- Create utils/sync.js (3 sync modes + conflict detection)
- Create utils/collection.js (collection management)
- Create utils/query-engine.js (client-side query parser)
- Rewrite background.js (sync loop, bookmark events, message routing)
- Rewrite popup.js (tabs, settings modal, notifications, CRUD)
- Update popup.html (tabbed interface, query builder, modal)
- Update popup.css (full redesign)
- Create content/content.js (page metadata extraction)
- Create options.html/js (dedicated settings page)
- Generate icons (48x48, 96x96)
- Update manifest.json (host permissions, content scripts, options)
- Create AGENTS.md

LinkSyncServer/alembic/env.py

@@ -0,0 +1,48 @@
+import os
+import sys
+from logging.config import fileConfig
+
+from sqlalchemy import engine_from_config, pool
+
+from alembic import context
+
+sys.path.insert(0, os.path.dirname(os.path.dirname(__file__)))
+
+from models.base import Base
+
+config = context.config
+
+if config.config_file_name is not None:
+    fileConfig(config.config_file_name)
+
+target_metadata = Base.metadata
+
+
+def run_migrations_offline() -> None:
+    url = config.get_main_option("sqlalchemy.url")
+    context.configure(
+        url=url,
+        target_metadata=target_metadata,
+        literal_binds=True,
+        dialect_opts={"paramstyle": "named"},
+    )
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def run_migrations_online() -> None:
+    connectable = engine_from_config(
+        config.get_section(config.config_ini_section, {}),
+        prefix="sqlalchemy.",
+        poolclass=pool.NullPool,
+    )
+    with connectable.connect() as connection:
+        context.configure(connection=connection, target_metadata=target_metadata)
+        with context.begin_transaction():
+            context.run_migrations()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()