feat: sync AI attribution governance from commit-check v2.11.0 (#16)

* feat: add AI attribution governance support from commit-check v2.11.0

Sync the new AI attribution governance feature from commit-check v2.11.0:
- Bump minimum commit-check dependency to >=2.11.0
- Add 'ai_attribution' to validate_commit_message and validate_commit_context
  check lists so the rule is actually executed
- Update README with AI attribution governance documentation

When config [commit] ai_attribution = "forbid" is set, commits containing
known AI tool signatures (Claude Code, GitHub Copilot, etc.) will be rejected.

* docs: Update README with AI attribution governance details

Added information about AI attribution governance in v2.11.0+.

Author: shenxianpeng

pyproject.toml

@@ -25,7 +25,7 @@ classifiers = [
   "Topic :: Software Development",
 ]
 dependencies = [
-  "commit-check>=2.7.0,<3",
+  "commit-check>=2.11.0,<3",
   "mcp>=1.27.0,<2"
 ]
 dynamic = ["version"]

src/commit_check_mcp/server.py

@@ -162,6 +162,7 @@ def _validate_message(
                 "allow_empty_commits",
                 "allow_fixup_commits",
                 "allow_wip_commits",
+                "ai_attribution",
             ],
             ValidationContext(stdin_text=message, config=cfg),
             cfg,
@@ -281,6 +282,7 @@ def _validate_all(
                         "allow_empty_commits",
                         "allow_fixup_commits",
                         "allow_wip_commits",
+                        "ai_attribution",
                     ],
                     ValidationContext(stdin_text=message, config=cfg),
                     cfg,