feat: add web UI with login, CRUD, admin, and API key management

- Add login page with JWT authentication
- Add dashboard with stats and quick actions
- Add links management page (full CRUD with search)
- Add collections management page
- Add API key management page with copy-to-clipboard
- Add admin user management page (admin only)
- Fix UUID type mismatches across all endpoints
- Add updated_at column to api_keys and audit_log in schema.sql
- Fix DB_PASSWORD default in docker-compose.yml
- Add PyJWT to requirements.txt
- Fix API docs URL (/docs instead of /api/docs)
- Improve JS error handling (show actual messages)
- Rewrite conftest.py with proper DB lifecycle management
- Add 42 new integration tests (84 total, all passing)
  - test_admin.py: 15 tests for admin endpoints
  - test_auth_extended.py: 9 tests for API key CRUD
  - test_tags.py: 12 tests for tag endpoints
  - test_sync.py: 6 tests for sync endpoints

LinkSyncServer/api/endpoints/auth.py

@@ -5,8 +5,9 @@ LinkSyncServer - Authentication Endpoints
 import hashlib
 import os
 import secrets
+import uuid
 from datetime import datetime, timedelta
-from typing import Optional
+from typing import List, Optional
 
 import bcrypt
 import jwt
@@ -178,6 +179,32 @@ async def logout():
     return {"message": "Logged out successfully"}
 
 
+@router.get("/api-keys", response_model=List[dict])
+async def list_api_keys(
+    current_user: dict = Depends(get_current_user),
+):
+    db = get_session()
+    try:
+        user = db.query(User).filter(User.username == current_user["username"]).first()
+        if not user:
+            raise HTTPException(status_code=404, detail="User not found")
+
+        api_keys = db.query(ApiKey).filter(ApiKey.user_id == user.id).order_by(ApiKey.created_at.desc()).all()
+        return [
+            {
+                "id": str(key.id),
+                "key_id": str(key.id),
+                "name": key.name,
+                "is_active": key.is_active,
+                "expires_at": key.expires_at.isoformat() if key.expires_at else None,
+                "created_at": key.created_at.isoformat() if key.created_at else None,
+            }
+            for key in api_keys
+        ]
+    finally:
+        db.close()
+
+
 @router.post("/api-key", response_model=ApiKeyResponse)
 async def create_api_key(
     name: str = "default",
@@ -204,7 +231,7 @@ async def create_api_key(
 
         return {
             "api_key": raw_key,
-            "key_id": api_key.id,
+            "key_id": str(api_key.id),
             "name": api_key.name,
             "expires_at": api_key.expires_at.isoformat() if api_key.expires_at else None,
         }
@@ -223,14 +250,19 @@ async def get_api_key_info(
         if not user:
             raise HTTPException(status_code=404, detail="User not found")
 
+        try:
+            parsed_key_id = uuid.UUID(key_id)
+        except (ValueError, AttributeError):
+            raise HTTPException(status_code=404, detail="API key not found")
+
         api_key = db.query(ApiKey).filter(
-            ApiKey.id == key_id, ApiKey.user_id == user.id
+            ApiKey.id == parsed_key_id, ApiKey.user_id == user.id
         ).first()
         if not api_key:
             raise HTTPException(status_code=404, detail="API key not found")
 
         return {
-            "key_id": api_key.id,
+            "key_id": str(api_key.id),
             "name": api_key.name,
             "is_active": api_key.is_active,
             "expires_at": api_key.expires_at.isoformat() if api_key.expires_at else None,
@@ -251,8 +283,13 @@ async def delete_api_key(
         if not user:
             raise HTTPException(status_code=404, detail="User not found")
 
+        try:
+            parsed_key_id = uuid.UUID(key_id)
+        except (ValueError, AttributeError):
+            raise HTTPException(status_code=404, detail="API key not found")
+
         api_key = db.query(ApiKey).filter(
-            ApiKey.id == key_id, ApiKey.user_id == user.id
+            ApiKey.id == parsed_key_id, ApiKey.user_id == user.id
         ).first()
         if not api_key:
             raise HTTPException(status_code=404, detail="API key not found")