fix(starlark): fix Python 3.13 importlib.reload() incompatibility (#258)

* fix(starlark): fix Python 3.13 importlib.reload() incompatibility

In Python 3.13, importlib.reload() raises ModuleNotFoundError for modules
loaded via spec_from_file_location when they aren't on sys.path, because
_bootstrap._find_spec() can no longer resolve them by name.

Replace the reload-on-cache-hit pattern in _get_tronbyte_repository_class()
and _get_pixlet_renderer_class() with a simple return of the cached class —
the reload was only useful for dev-time iteration and is unnecessary in
production (the service restarts clean on each deploy).

Also broaden the exception catch in upload_starlark_app() from
(ValueError, OSError, IOError) to Exception so that any unexpected error
(ImportError, ModuleNotFoundError, etc.) returns a proper JSON response
instead of an unhandled Flask 500.

Fixes: "Install failed: spec not found for the module 'tronbyte_repository'"

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* fix(starlark): use targeted exception handlers in upload_starlark_app()

Replace the broad `except Exception` catch-all with specific handlers:
- (OSError, IOError) for temp file creation/save failures
- ImportError for module loading failures (_get_pixlet_renderer_class)
- Exception as final catch-all that logs without leaking internals

All handlers use `err` (not unused `e`) in both the log message and
the JSON response body.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Chuck <chuck@example.com>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

web_interface/blueprints/api_v3.py

@@ -6989,9 +6989,8 @@ def _get_tronbyte_repository_class() -> Type[Any]:
     if not module_path.exists():
         raise ImportError(f"TronbyteRepository module not found at {module_path}")
 
-    # If already imported, reload to pick up code changes
+    # If already imported, return cached class
     if "tronbyte_repository" in sys.modules:
-        importlib.reload(sys.modules["tronbyte_repository"])
         return sys.modules["tronbyte_repository"].TronbyteRepository
 
     spec = importlib.util.spec_from_file_location("tronbyte_repository", str(module_path))
@@ -7016,9 +7015,8 @@ def _get_pixlet_renderer_class() -> Type[Any]:
     if not module_path.exists():
         raise ImportError(f"PixletRenderer module not found at {module_path}")
 
-    # If already imported, reload to pick up code changes
+    # If already imported, return cached class
     if "pixlet_renderer" in sys.modules:
-        importlib.reload(sys.modules["pixlet_renderer"])
         return sys.modules["pixlet_renderer"].PixletRenderer
 
     spec = importlib.util.spec_from_file_location("pixlet_renderer", str(module_path))
@@ -7442,8 +7440,14 @@ def upload_starlark_app():
             except OSError:
                 pass
 
-    except (ValueError, OSError, IOError) as e:
+    except (OSError, IOError) as err:
-        logger.exception("[Starlark] Error uploading starlark app")
+        logger.exception("[Starlark] File error uploading starlark app: %s", err)
+        return jsonify({'status': 'error', 'message': f'File error during upload: {err}'}), 500
+    except ImportError as err:
+        logger.exception("[Starlark] Module load error uploading starlark app: %s", err)
+        return jsonify({'status': 'error', 'message': f'Failed to load app module: {err}'}), 500
+    except Exception as err:
+        logger.exception("[Starlark] Unexpected error uploading starlark app: %s", err)
         return jsonify({'status': 'error', 'message': 'Failed to upload app'}), 500