Enhance packages API with pagination, filtering, and metadata

Backend changes:
- Add format and platform columns to Package model with validation
- Add database migrations for new columns with indexes
- Create PackageDetailResponse schema with aggregated fields:
  - tag_count, artifact_count, total_size
  - latest_tag, latest_upload_at
  - recent_tags (last 5 tags)
- Update list_packages endpoint:
  - Add pagination (page, limit)
  - Add search by name/description
  - Add sort (name, created_at, updated_at) and order (asc, desc)
  - Add format and platform filters
  - Return aggregated metadata for each package
- Add GET /api/v1/project/{project}/packages/{package_name} endpoint
  - Returns single package with full metadata
  - Optional include_tags parameter for all tags
- Update create_package to accept format and platform

Frontend changes:
- Update Package type with format, platform, and optional metadata fields
- Update listPackages to handle paginated response

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

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

backend/app/schemas.py

@@ -39,10 +39,17 @@ class ProjectResponse(BaseModel):
         from_attributes = True
 
 
+# Package format and platform enums
+PACKAGE_FORMATS = ["generic", "npm", "pypi", "docker", "deb", "rpm", "maven", "nuget", "helm"]
+PACKAGE_PLATFORMS = ["any", "linux", "darwin", "windows", "linux-amd64", "linux-arm64", "darwin-amd64", "darwin-arm64", "windows-amd64"]
+
+
 # Package schemas
 class PackageCreate(BaseModel):
     name: str
     description: Optional[str] = None
+    format: str = "generic"
+    platform: str = "any"
 
 
 class PackageResponse(BaseModel):
@@ -50,6 +57,8 @@ class PackageResponse(BaseModel):
     project_id: UUID
     name: str
     description: Optional[str]
+    format: str
+    platform: str
     created_at: datetime
     updated_at: datetime
 
@@ -57,6 +66,36 @@ class PackageResponse(BaseModel):
         from_attributes = True
 
 
+class TagSummary(BaseModel):
+    """Lightweight tag info for embedding in package responses"""
+    name: str
+    artifact_id: str
+    created_at: datetime
+
+
+class PackageDetailResponse(BaseModel):
+    """Package with aggregated metadata"""
+    id: UUID
+    project_id: UUID
+    name: str
+    description: Optional[str]
+    format: str
+    platform: str
+    created_at: datetime
+    updated_at: datetime
+    # Aggregated fields
+    tag_count: int = 0
+    artifact_count: int = 0
+    total_size: int = 0
+    latest_tag: Optional[str] = None
+    latest_upload_at: Optional[datetime] = None
+    # Recent tags (limit 5)
+    recent_tags: List[TagSummary] = []
+
+    class Config:
+        from_attributes = True
+
+
 # Artifact schemas
 class ArtifactResponse(BaseModel):
     id: str