fix: make category free-form, keep effect validated

Category is a free-form string (only validated as non-empty when present),
while effect remains restricted to 'read-only' or 'read-write'.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: mnriem

.github/skills/add-community-extension/SKILL.md

@@ -89,7 +89,7 @@ Use the existing entries as the format template. Required fields:
 }
 ```
 
-**Category** — one of: `docs`, `code`, `process`, `integration`, `visibility`
+**Category** — free-form string; common values: `docs`, `code`, `process`, `integration`, `visibility`
 **Effect** — one of: `read-only`, `read-write`
 
 If the extension has optional tool dependencies, add a `"tools"` array inside `"requires"`:
@@ -118,7 +118,7 @@ Determine the category and effect from the extension's behavior:
 | <Name> | <Description> | `<category>` | <Effect> | [<repo-name>](<repository-url>) |
 ```
 
-**Category** — one of: `docs`, `code`, `process`, `integration`, `visibility`
+**Category** — free-form; common values: `docs`, `code`, `process`, `integration`, `visibility`
 **Effect** — `Read-only` (produces reports only) or `Read+Write` (modifies project files)
 
 ### 6. Commit, push, and open PR

docs/community/extensions.md

@@ -7,7 +7,7 @@
 
 The following community-contributed extensions are available in [`catalog.community.json`](https://github.com/github/spec-kit/blob/main/extensions/catalog.community.json):
 
-**Categories:**
+**Categories** (common values, but any string is allowed):
 
 - `docs` — reads, validates, or generates spec artifacts
 - `code` — reviews, validates, or modifies source code

extensions/template/extension.yml

@@ -14,7 +14,7 @@ extension:
   description: "Brief description of what your extension does"
 
   # CUSTOMIZE: Extension category — describes what the extension operates on
-  # One of: docs | code | process | integration | visibility
+  # Common values: docs, code, process, integration, visibility
   category: "process"
 
   # CUSTOMIZE: Extension effect — whether it modifies project files

src/specify_cli/extensions.py

@@ -41,7 +41,6 @@
 })
 EXTENSION_COMMAND_NAME_PATTERN = re.compile(r"^speckit\.([a-z0-9-]+)\.([a-z0-9-]+)$")
 
-VALID_CATEGORIES = frozenset({"docs", "code", "process", "integration", "visibility"})
 VALID_EFFECTS = frozenset({"read-only", "read-write"})
 
 DEFAULT_HOOK_PRIORITY = 10
@@ -204,12 +203,11 @@ def _validate(self):
         except pkg_version.InvalidVersion:
             raise ValidationError(f"Invalid version: {ext['version']}")
 
-        # Validate optional category field
+        # Validate optional category field (free-form string)
         if "category" in ext:
-            if ext["category"] not in VALID_CATEGORIES:
+            if not isinstance(ext["category"], str) or not ext["category"].strip():
                 raise ValidationError(
-                    f"Invalid extension.category '{ext['category']}': "
-                    f"must be one of {sorted(VALID_CATEGORIES)}"
+                    "Invalid extension.category: must be a non-empty string"
                 )
 
         # Validate optional effect field

tests/test_extensions.py

@@ -24,7 +24,6 @@
     CatalogEntry,
     CORE_COMMAND_NAMES,
     DEFAULT_HOOK_PRIORITY,
-    VALID_CATEGORIES,
     VALID_EFFECTS,
     ExtensionManifest,
     ExtensionRegistry,
@@ -303,10 +302,10 @@ def test_invalid_version(self, temp_dir, valid_manifest_data):
             ExtensionManifest(manifest_path)
 
     def test_valid_category(self, temp_dir, valid_manifest_data):
-        """Test manifest with valid category values."""
+        """Test manifest with various category values (free-form string)."""
         import yaml
 
-        for category in ("docs", "code", "process", "integration", "visibility"):
+        for category in ("docs", "code", "process", "integration", "visibility", "custom-category"):
             valid_manifest_data["extension"]["category"] = category
             manifest_path = temp_dir / "extension.yml"
             with open(manifest_path, 'w') as f:
@@ -327,10 +326,10 @@ def test_valid_effect(self, temp_dir, valid_manifest_data):
             assert manifest.effect == effect
 
     def test_invalid_category(self, temp_dir, valid_manifest_data):
-        """Test manifest with invalid category raises ValidationError."""
+        """Test manifest with empty category raises ValidationError."""
         import yaml
 
-        valid_manifest_data["extension"]["category"] = "invalid-category"
+        valid_manifest_data["extension"]["category"] = ""
         manifest_path = temp_dir / "extension.yml"
         with open(manifest_path, 'w') as f:
             yaml.dump(valid_manifest_data, f)