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/webhook.py

@@ -0,0 +1,98 @@
+"""Webhook schemas."""
+
+from datetime import datetime
+from typing import Optional, List
+from pydantic import BaseModel, HttpUrl, Field
+
+
+# Webhook Base
+class WebhookBase(BaseModel):
+    """Base webhook schema."""
+    name: str = Field(..., min_length=1, max_length=100)
+    url: str = Field(..., min_length=1, max_length=500)
+    events: List[str] = Field(default=["*"])
+    is_active: bool = True
+    retry_count: int = Field(default=3, ge=0, le=10)
+    timeout_seconds: int = Field(default=30, ge=5, le=120)
+
+
+class WebhookCreate(WebhookBase):
+    """Schema for creating a webhook."""
+    pass
+
+
+class WebhookUpdate(BaseModel):
+    """Schema for updating a webhook."""
+    name: Optional[str] = Field(None, min_length=1, max_length=100)
+    url: Optional[str] = Field(None, min_length=1, max_length=500)
+    events: Optional[List[str]] = None
+    is_active: Optional[bool] = None
+    retry_count: Optional[int] = Field(None, ge=0, le=10)
+    timeout_seconds: Optional[int] = Field(None, ge=5, le=120)
+
+
+class Webhook(WebhookBase):
+    """Webhook response schema."""
+    id: str
+    secret: Optional[str] = None
+    created_by: Optional[str] = None
+    created_at: datetime
+    updated_at: datetime
+    last_triggered_at: Optional[datetime] = None
+    success_count: int
+    failure_count: int
+
+    class Config:
+        from_attributes = True
+
+
+class WebhookWithSecret(Webhook):
+    """Webhook response with secret (for creation)."""
+    secret: str
+
+
+# Webhook Delivery
+class WebhookDeliveryBase(BaseModel):
+    """Base webhook delivery schema."""
+    webhook_id: str
+    event_type: str
+    payload: str
+
+
+class WebhookDelivery(WebhookDeliveryBase):
+    """Webhook delivery response schema."""
+    id: str
+    status: str
+    status_code: Optional[int] = None
+    response_body: Optional[str] = None
+    error_message: Optional[str] = None
+    attempt_count: int
+    next_retry_at: Optional[datetime] = None
+    created_at: datetime
+    delivered_at: Optional[datetime] = None
+
+    class Config:
+        from_attributes = True
+
+
+# Event types
+WEBHOOK_EVENTS = [
+    "user.created",
+    "user.updated",
+    "user.deleted",
+    "user.login",
+    "user.logout",
+    "user.password_changed",
+    "user.2fa_enabled",
+    "user.2fa_disabled",
+    "settings.updated",
+    "api_key.created",
+    "api_key.revoked",
+    "*",  # All events
+]
+
+
+class WebhookTest(BaseModel):
+    """Schema for testing a webhook."""
+    event_type: str = "test.ping"
+    payload: Optional[dict] = None