Remove public internet features and fix upstream source UI (#107)

- Remove is_public field from upstream sources (all sources are internal)
- Remove allow_public_internet setting from cache settings
- Remove seeding of public registry URLs
- Fix connectivity test to not follow redirects (fixes Artifactory error)
- Add dedicated Test column with OK/Error status badges
- Auto-test sources after save
- Add error modal for viewing full error details
- Fix table layout (no-wrap on source name)
- Add ORCHARD_PURGE_SEED_DATA to stage helm values

backend/app/schemas.py

@@ -1214,7 +1214,6 @@ class UpstreamSourceCreate(BaseModel):
     source_type: str = "generic"
     url: str
     enabled: bool = False
-    is_public: bool = True
     auth_type: str = "none"
     username: Optional[str] = None
     password: Optional[str] = None  # Write-only
@@ -1271,7 +1270,6 @@ class UpstreamSourceUpdate(BaseModel):
     source_type: Optional[str] = None
     url: Optional[str] = None
     enabled: Optional[bool] = None
-    is_public: Optional[bool] = None
     auth_type: Optional[str] = None
     username: Optional[str] = None
     password: Optional[str] = None  # Write-only, None = keep existing, empty string = clear
@@ -1331,7 +1329,6 @@ class UpstreamSourceResponse(BaseModel):
     source_type: str
     url: str
     enabled: bool
-    is_public: bool
     auth_type: str
     username: Optional[str]
     has_password: bool  # True if password is set
@@ -1347,9 +1344,7 @@ class UpstreamSourceResponse(BaseModel):
 
 class CacheSettingsResponse(BaseModel):
     """Global cache settings response"""
-    allow_public_internet: bool
     auto_create_system_projects: bool
-    allow_public_internet_env_override: Optional[bool] = None  # Set if overridden by env var
     auto_create_system_projects_env_override: Optional[bool] = None  # Set if overridden by env var
     created_at: Optional[datetime] = None  # May be None for legacy data
     updated_at: Optional[datetime] = None  # May be None for legacy data
@@ -1360,7 +1355,6 @@ class CacheSettingsResponse(BaseModel):
 
 class CacheSettingsUpdate(BaseModel):
     """Update cache settings (partial)"""
-    allow_public_internet: Optional[bool] = None
     auto_create_system_projects: Optional[bool] = None