fix: prefer repo-relative hook file paths

scripts/hooks/session-activity-tracker.js

@@ -359,17 +359,10 @@ function gitRepoRoot(cwd) {
   return runGit(['rev-parse', '--show-toplevel'], cwd);
 }
 
+const MAX_RELEVANT_PATCH_LINES = 6;
+
 function candidateGitPaths(repoRoot, filePath) {
   const resolvedRepoRoot = path.resolve(repoRoot);
-  const absolute = path.isAbsolute(filePath)
-    ? path.resolve(filePath)
-    : path.resolve(process.cwd(), filePath);
-  const relative = path.relative(resolvedRepoRoot, absolute);
-
-  if (!relative || relative.startsWith('..') || path.isAbsolute(relative)) {
-    return [];
-  }
-
   const candidates = [];
   const pushCandidate = value => {
     const candidate = String(value || '').trim();
@@ -379,10 +372,24 @@ function candidateGitPaths(repoRoot, filePath) {
     candidates.push(candidate);
   };
 
-  pushCandidate(relative);
-  pushCandidate(relative.split(path.sep).join('/'));
-  pushCandidate(absolute);
-  pushCandidate(absolute.split(path.sep).join('/'));
+  const absoluteCandidates = path.isAbsolute(filePath)
+    ? [path.resolve(filePath)]
+    : [
+        path.resolve(resolvedRepoRoot, filePath),
+        path.resolve(process.cwd(), filePath),
+      ];
+
+  for (const absolute of absoluteCandidates) {
+    const relative = path.relative(resolvedRepoRoot, absolute);
+    if (!relative || relative.startsWith('..') || path.isAbsolute(relative)) {
+      continue;
+    }
+
+    pushCandidate(relative);
+    pushCandidate(relative.split(path.sep).join('/'));
+    pushCandidate(absolute);
+    pushCandidate(absolute.split(path.sep).join('/'));
+  }
 
   return candidates;
 }
@@ -404,7 +411,7 @@ function patchPreviewFromGitDiff(repoRoot, pathCandidates) {
           || (line.startsWith('+') && !line.startsWith('+++'))
           || (line.startsWith('-') && !line.startsWith('---'))
       )
-      .slice(0, 6);
+      .slice(0, MAX_RELEVANT_PATCH_LINES);
 
     if (relevant.length > 0) {
       return relevant.join('\n');

tests/hooks/session-activity-tracker.test.js

@@ -309,6 +309,58 @@ function runTests() {
     fs.rmSync(repoDir, { recursive: true, force: true });
   }) ? passed++ : failed++);
 
+  (test('resolves repo-relative paths even when the hook runs from a nested cwd', () => {
+    const tmpHome = makeTempDir();
+    const repoDir = fs.mkdtempSync(path.join(os.tmpdir(), 'session-activity-tracker-nested-repo-'));
+
+    spawnSync('git', ['init'], { cwd: repoDir, encoding: 'utf8' });
+    spawnSync('git', ['config', 'user.email', 'ecc@example.com'], { cwd: repoDir, encoding: 'utf8' });
+    spawnSync('git', ['config', 'user.name', 'ECC Tests'], { cwd: repoDir, encoding: 'utf8' });
+
+    const srcDir = path.join(repoDir, 'src');
+    const nestedCwd = path.join(repoDir, 'subdir');
+    fs.mkdirSync(srcDir, { recursive: true });
+    fs.mkdirSync(nestedCwd, { recursive: true });
+
+    const trackedFile = path.join(srcDir, 'app.ts');
+    fs.writeFileSync(trackedFile, 'const count = 1;\n', 'utf8');
+    spawnSync('git', ['add', 'src/app.ts'], { cwd: repoDir, encoding: 'utf8' });
+    spawnSync('git', ['commit', '-m', 'init'], { cwd: repoDir, encoding: 'utf8' });
+
+    fs.writeFileSync(trackedFile, 'const count = 2;\n', 'utf8');
+
+    const input = {
+      tool_name: 'Write',
+      tool_input: {
+        file_path: 'src/app.ts',
+        content: 'const count = 2;\n',
+      },
+      tool_output: { output: 'updated src/app.ts' },
+    };
+    const result = runScript(input, {
+      ...withTempHome(tmpHome),
+      CLAUDE_HOOK_EVENT_NAME: 'PostToolUse',
+      ECC_SESSION_ID: 'ecc-session-nested-cwd',
+    }, {
+      cwd: nestedCwd,
+    });
+    assert.strictEqual(result.code, 0);
+
+    const metricsFile = path.join(tmpHome, '.claude', 'metrics', 'tool-usage.jsonl');
+    const row = JSON.parse(fs.readFileSync(metricsFile, 'utf8').trim());
+    assert.deepStrictEqual(row.file_events, [
+      {
+        path: 'src/app.ts',
+        action: 'modify',
+        diff_preview: 'const count = 1; -> const count = 2;',
+        patch_preview: '@@ -1 +1 @@\n-const count = 1;\n+const count = 2;',
+      },
+    ]);
+
+    fs.rmSync(tmpHome, { recursive: true, force: true });
+    fs.rmSync(repoDir, { recursive: true, force: true });
+  }) ? passed++ : failed++);
+
   (test('prefers ECC_SESSION_ID over CLAUDE_SESSION_ID and redacts bash summaries', () => {
     const tmpHome = makeTempDir();
     const input = {