Add comprehensive backend features and mobile UI improvements

Backend:
- Add 2FA authentication with TOTP support
- Add API keys management system
- Add audit logging for security events
- Add file upload/management system
- Add notifications system with preferences
- Add session management
- Add webhooks integration
- Add analytics endpoints
- Add export functionality
- Add password policy enforcement
- Add new database migrations for core tables

Frontend:
- Add module position system (top/bottom sidebar sections)
- Add search and notifications module configuration tabs
- Add mobile logo replacing hamburger menu
- Center page title absolutely when no tabs present
- Align sidebar footer toggles with navigation items
- Add lighter icon color in dark theme for mobile
- Add API keys management page
- Add notifications page with context
- Add admin analytics and audit logs pages

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/app/schemas/api_key.py

@@ -0,0 +1,55 @@
+"""Pydantic schemas for API Key requests/responses."""
+
+from datetime import datetime
+from typing import Optional, List
+from pydantic import BaseModel, Field
+
+
+class APIKeyBase(BaseModel):
+    """Base API key schema."""
+    name: str = Field(..., min_length=1, max_length=100)
+    scopes: Optional[List[str]] = None
+    expires_at: Optional[datetime] = None
+
+
+class APIKeyCreate(APIKeyBase):
+    """Schema for creating an API key."""
+    pass
+
+
+class APIKeyUpdate(BaseModel):
+    """Schema for updating an API key."""
+    name: Optional[str] = Field(None, min_length=1, max_length=100)
+    scopes: Optional[List[str]] = None
+    is_active: Optional[bool] = None
+    expires_at: Optional[datetime] = None
+
+
+class APIKey(BaseModel):
+    """Schema for API key response (without the actual key)."""
+    id: str
+    user_id: str
+    name: str
+    key_prefix: str
+    scopes: Optional[List[str]] = None
+    is_active: bool
+    last_used_at: Optional[datetime] = None
+    last_used_ip: Optional[str] = None
+    usage_count: int = 0
+    expires_at: Optional[datetime] = None
+    created_at: datetime
+    updated_at: datetime
+
+    class Config:
+        from_attributes = True
+
+
+class APIKeyWithSecret(APIKey):
+    """Schema for API key response with the actual key (only on creation)."""
+    key: str  # The actual API key - only shown once
+
+
+class APIKeyList(BaseModel):
+    """Schema for paginated API key list."""
+    items: List[APIKey]
+    total: int