Add organization and task queue features

- Introduced new models for `Organization` and `ReviewTask` to manage organizations and review tasks.
- Implemented API endpoints for CRUD operations on organizations and tasks, including scanning organizations for repositories and PRs.
- Developed a background worker for sequential processing of review tasks with priority handling and automatic retries.
- Created frontend components for managing organizations and monitoring task queues, including real-time updates and filtering options.
- Added comprehensive documentation for organization features and quick start guides.
- Fixed UI issues and improved navigation for better user experience.

backend/app/schemas/organization.py

@@ -0,0 +1,60 @@
+"""Organization schemas"""
+
+from pydantic import BaseModel, Field
+from typing import Optional, Dict, Any, List
+from datetime import datetime
+from app.models.organization import OrganizationPlatformEnum
+
+
+class OrganizationBase(BaseModel):
+    """Base organization schema"""
+    name: str = Field(..., description="Organization name")
+    platform: OrganizationPlatformEnum = Field(..., description="Git platform")
+    base_url: str = Field(..., description="Base URL (e.g., https://git.example.com)")
+    config: Optional[Dict[str, Any]] = Field(default_factory=dict, description="Review configuration")
+
+
+class OrganizationCreate(OrganizationBase):
+    """Schema for creating organization"""
+    api_token: Optional[str] = Field(None, description="API token (optional, uses master token if not set)")
+    webhook_secret: Optional[str] = Field(None, description="Webhook secret (generated if not provided)")
+
+
+class OrganizationUpdate(BaseModel):
+    """Schema for updating organization"""
+    name: Optional[str] = None
+    base_url: Optional[str] = None
+    api_token: Optional[str] = None
+    webhook_secret: Optional[str] = None
+    config: Optional[Dict[str, Any]] = None
+    is_active: Optional[bool] = None
+
+
+class OrganizationResponse(OrganizationBase):
+    """Schema for organization response"""
+    id: int
+    is_active: bool
+    last_scan_at: Optional[datetime]
+    created_at: datetime
+    updated_at: datetime
+    webhook_url: str = Field(..., description="Webhook URL for this organization")
+    
+    class Config:
+        from_attributes = True
+
+
+class OrganizationList(BaseModel):
+    """Schema for organization list response"""
+    items: List[OrganizationResponse]
+    total: int
+
+
+class OrganizationScanResult(BaseModel):
+    """Schema for organization scan result"""
+    organization_id: int
+    repositories_found: int
+    repositories_added: int
+    pull_requests_found: int
+    tasks_created: int
+    errors: List[str] = []
+