feat(KIN-010): implement rebuild-frontend post-pipeline hook

- scripts/rebuild-frontend.sh: builds Vue 3 frontend and restarts uvicorn API
- cli/main.py: hook group with add/list/remove/logs/setup commands;
  `hook setup` idempotently registers rebuild-frontend for a project
- agents/runner.py: call run_hooks(event="pipeline_completed") after
  successful pipeline; wrap in try/except so hook errors never block results
- tests: 3 tests for hook_setup CLI + 3 tests for pipeline→hooks integration

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

tests/test_runner.py

@@ -249,6 +249,45 @@ class TestRunPipeline:
         assert result["success"] is False
         assert "not found" in result["error"]
 
+    @patch("agents.runner.run_hooks")
+    @patch("agents.runner.subprocess.run")
+    def test_hooks_called_after_successful_pipeline(self, mock_run, mock_hooks, conn):
+        mock_run.return_value = _mock_claude_success({"result": "done"})
+        mock_hooks.return_value = []
+
+        steps = [{"role": "debugger", "brief": "find"}]
+        result = run_pipeline(conn, "VDOL-001", steps)
+
+        assert result["success"] is True
+        mock_hooks.assert_called_once()
+        call_kwargs = mock_hooks.call_args
+        assert call_kwargs[1].get("event") == "pipeline_completed" or \
+               call_kwargs[0][3] == "pipeline_completed"
+
+    @patch("agents.runner.run_hooks")
+    @patch("agents.runner.subprocess.run")
+    def test_hooks_not_called_on_failed_pipeline(self, mock_run, mock_hooks, conn):
+        mock_run.return_value = _mock_claude_failure("compilation error")
+        mock_hooks.return_value = []
+
+        steps = [{"role": "debugger", "brief": "find"}]
+        result = run_pipeline(conn, "VDOL-001", steps)
+
+        assert result["success"] is False
+        mock_hooks.assert_not_called()
+
+    @patch("agents.runner.run_hooks")
+    @patch("agents.runner.subprocess.run")
+    def test_hook_failure_does_not_affect_pipeline_result(self, mock_run, mock_hooks, conn):
+        mock_run.return_value = _mock_claude_success({"result": "done"})
+        mock_hooks.side_effect = Exception("hook exploded")
+
+        steps = [{"role": "debugger", "brief": "find"}]
+        # Must not raise — hook failures must not propagate
+        result = run_pipeline(conn, "VDOL-001", steps)
+
+        assert result["success"] is True
+
 
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