Add global search and filtering enhancements

- Add GET /api/v1/search endpoint for cross-entity search
- Add visibility filter to projects list API
- Enhance tag search to include artifact original filename
- Fix project list sorting to use sort/order parameters
- Add GlobalSearch component with keyboard navigation and "/" shortcut
- Add FilterDropdown component for reusable filter dropdowns
- Add visibility filter UI to Home page with URL persistence
- Update API types and functions for global search

backend/app/schemas.py

@@ -269,6 +269,51 @@ class ConsumerResponse(BaseModel):
         from_attributes = True
 
 
+# Global search schemas
+class SearchResultProject(BaseModel):
+    """Project result for global search"""
+    id: UUID
+    name: str
+    description: Optional[str]
+    is_public: bool
+
+    class Config:
+        from_attributes = True
+
+
+class SearchResultPackage(BaseModel):
+    """Package result for global search"""
+    id: UUID
+    project_id: UUID
+    project_name: str
+    name: str
+    description: Optional[str]
+    format: str
+
+    class Config:
+        from_attributes = True
+
+
+class SearchResultArtifact(BaseModel):
+    """Artifact/tag result for global search"""
+    tag_id: UUID
+    tag_name: str
+    artifact_id: str
+    package_id: UUID
+    package_name: str
+    project_name: str
+    original_name: Optional[str]
+
+
+class GlobalSearchResponse(BaseModel):
+    """Combined search results across all entity types"""
+    query: str
+    projects: List[SearchResultProject]
+    packages: List[SearchResultPackage]
+    artifacts: List[SearchResultArtifact]
+    counts: Dict[str, int]  # Total counts for each type
+
+
 # Health check
 class HealthResponse(BaseModel):
     status: str