fix: narrow exception catch in extension manifest parsing

Replace broad 'except Exception: pass' with specific exception types
(ExtValidationError, yaml.YAMLError) and add explanatory comment for
the intentional fallback to convention-based lookup.

Author: mnriem

src/specify_cli/presets.py

@@ -2327,7 +2327,7 @@ def _find_in_subdirs(base_dir: Path) -> Optional[Path]:
                 ext_manifest_path = ext_dir / "extension.yml"
                 if ext_manifest_path.exists():
                     try:
-                        from .extensions import ExtensionManifest
+                        from .extensions import ExtensionManifest, ValidationError as ExtValidationError
                         ext_manifest = ExtensionManifest(ext_manifest_path)
                         for cmd in ext_manifest.commands:
                             if cmd.get("name") == template_name:
@@ -2337,7 +2337,9 @@ def _find_in_subdirs(base_dir: Path) -> Optional[Path]:
                                     if c.exists():
                                         candidate = c
                                 break
-                    except Exception:
+                    except (ExtValidationError, yaml.YAMLError):
+                        # Invalid extension manifest — fall back to
+                        # convention-based lookup (already attempted above).
                         pass
             if candidate:
                 if ext_meta: