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/config.py

@@ -61,8 +61,7 @@ class Settings(BaseSettings):
 
     # Cache settings
     cache_encryption_key: str = ""  # Fernet key for encrypting upstream credentials (auto-generated if empty)
-    # Global cache settings overrides (None = use DB value, True/False = override DB)
-    cache_allow_public_internet: Optional[bool] = None  # Override allow_public_internet (air-gap mode)
+    # Global cache settings override (None = use DB value, True/False = override DB)
     cache_auto_create_system_projects: Optional[bool] = None  # Override auto_create_system_projects
 
     # JWT Authentication settings (optional, for external identity providers)
@@ -108,7 +107,6 @@ class EnvUpstreamSource:
         url: str,
         source_type: str = "generic",
         enabled: bool = True,
-        is_public: bool = True,
         auth_type: str = "none",
         username: Optional[str] = None,
         password: Optional[str] = None,
@@ -118,7 +116,6 @@ class EnvUpstreamSource:
         self.url = url
         self.source_type = source_type
         self.enabled = enabled
-        self.is_public = is_public
         self.auth_type = auth_type
         self.username = username
         self.password = password
@@ -188,7 +185,6 @@ def parse_upstream_sources_from_env() -> list[EnvUpstreamSource]:
             url=url,
             source_type=data.get("TYPE", "generic").lower(),
             enabled=parse_bool(data.get("ENABLED"), True),
-            is_public=parse_bool(data.get("IS_PUBLIC"), True),
             auth_type=data.get("AUTH_TYPE", "none").lower(),
             username=data.get("USERNAME"),
             password=data.get("PASSWORD"),