fix(hooks): point update-graph.sh fallback build path at dist/cli.js

The PostToolUse hook's fallback branch (used when the codegraph binary
isn't on PATH) invoked node against src/cli.js, a file that has never
existed in this repo. The CLI entry point is TypeScript at src/cli.ts,
compiled to dist/cli.js per package.json's bin.codegraph. Since stderr
is redirected to /dev/null, the branch failed silently and the graph
never rebuilt for contributors without a global codegraph install.

Add a regression test asserting the hook never references src/cli.js
and does invoke package.json's bin.codegraph entry point.

Author: carlos-alm

.claude/hooks/update-graph.sh

@@ -97,7 +97,7 @@ BUILD_OK=0
 if command -v codegraph &>/dev/null; then
   codegraph build "$PROJECT_DIR" -d "$DB_PATH" $BUILD_FLAGS 2>/dev/null && BUILD_OK=1 || true
 else
-  node "${CLAUDE_PROJECT_DIR:-$PROJECT_DIR}/src/cli.js" build "$PROJECT_DIR" -d "$DB_PATH" $BUILD_FLAGS 2>/dev/null && BUILD_OK=1 || true
+  node "${CLAUDE_PROJECT_DIR:-$PROJECT_DIR}/dist/cli.js" build "$PROJECT_DIR" -d "$DB_PATH" $BUILD_FLAGS 2>/dev/null && BUILD_OK=1 || true
 fi
 
 # Update marker only if we did a full rebuild AND it succeeded

tests/unit/hook-fallback-build-path.test.ts

@@ -0,0 +1,31 @@
+/**
+ * Regression guard for issue #1836: .claude/hooks/update-graph.sh's
+ * fallback build path (used when the `codegraph` binary isn't on PATH)
+ * invoked `node <project>/src/cli.js`, a file that has never existed —
+ * the CLI entry point is TypeScript at src/cli.ts, compiled to dist/cli.js
+ * (see package.json's `bin.codegraph`). That branch silently failed
+ * (stderr redirected to /dev/null), so BUILD_OK stayed 0 and the graph
+ * never rebuilt for contributors without a global codegraph install.
+ */
+import fs from 'node:fs';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { describe, expect, it } from 'vitest';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+const REPO_ROOT = path.resolve(__dirname, '..', '..');
+const HOOK_PATH = path.join(REPO_ROOT, '.claude', 'hooks', 'update-graph.sh');
+
+describe('update-graph.sh hook fallback build path', () => {
+  const script = fs.readFileSync(HOOK_PATH, 'utf8');
+  const packageJson = JSON.parse(fs.readFileSync(path.join(REPO_ROOT, 'package.json'), 'utf8'));
+  const cliEntry = packageJson.bin.codegraph.replace(/^\.\//, '');
+
+  it('never references a nonexistent src/cli.js', () => {
+    expect(script).not.toMatch(/\bsrc\/cli\.js\b/);
+  });
+
+  it("invokes package.json's bin.codegraph entry point in the fallback branch", () => {
+    expect(script).toContain(`/${cliEntry}" build`);
+  });
+});