diff --git a/.changeset/jolly-pumas-dance.md b/.changeset/jolly-pumas-dance.md
new file mode 100644
index 000000000..28b09701e
--- /dev/null
+++ b/.changeset/jolly-pumas-dance.md
@@ -0,0 +1,5 @@
+---
+type: Fixed
+pr: 2979
+---
+Managed JS hooks now resolve under GUI/minimal-PATH runtimes — installer emits process.execPath (absolute, quoted, forward-slash-normalized) as the runner for every .js hook command instead of bare node. See #2979.
diff --git a/.changeset/zesty-jays-wake.md b/.changeset/zesty-jays-wake.md
new file mode 100644
index 000000000..28b09701e
--- /dev/null
+++ b/.changeset/zesty-jays-wake.md
@@ -0,0 +1,5 @@
+---
+type: Fixed
+pr: 2979
+---
+Managed JS hooks now resolve under GUI/minimal-PATH runtimes — installer emits process.execPath (absolute, quoted, forward-slash-normalized) as the runner for every .js hook command instead of bare node. See #2979.
diff --git a/bin/install.js b/bin/install.js
index 390f912d5..1813274d8 100755
--- a/bin/install.js
+++ b/bin/install.js
@@ -525,6 +525,82 @@ function computePathPrefix({ isGlobal, isOpencode, isWindowsHost: _isWindowsHost
   return `${resolvedTarget}/`;
 }
 
+/**
+ * Resolve the absolute path to the node binary running the installer.
+ * Used as the runner for .js hooks so they execute in GUI/minimal-PATH
+ * runtimes (Gemini, Antigravity, Codex CLIs launched from a Finder
+ * shortcut etc.) where bare `node` is not on `/usr/bin:/bin:/usr/sbin:/sbin`
+ * and the hook would fail with `node: command not found` (#2979).
+ *
+ * Returns a forward-slash-normalized, double-quoted path so the emitted
+ * command is shell-safe across POSIX and Windows. `process.execPath`
+ * gives the absolute path of the node binary actively running the
+ * installer — that is the version the user just installed under, and
+ * the right default runtime for hooks invoked under the same install.
+ */
+function resolveNodeRunner() {
+  const execPath = typeof process.execPath === 'string' ? process.execPath : '';
+  if (!execPath) return null;
+  // JSON.stringify produces a properly escaped double-quoted shell token,
+  // safe for paths containing spaces or unusual characters.
+  return JSON.stringify(execPath.replace(/\\/g, '/'));
+}
+
+/**
+ * Rewrite legacy `node .../gsd-*.js` command strings in settings.hooks to use
+ * the absolute Node binary path (#2979 follow-up: CR feedback on #3002).
+ *
+ * The original #2979 fix only emitted absolute paths for *newly registered*
+ * hooks. Pre-existing entries kept their bare `node ` prefix on reinstall,
+ * which left them broken under minimal-PATH GUI runtimes — exactly the
+ * failure mode the original fix was meant to close. This walker normalizes
+ * any managed-hook entry whose command starts with bare `node ` to
+ * `<absoluteRunner> <script>` while leaving non-managed and non-bare-node
+ * entries (user-authored hooks, shell scripts, etc.) untouched.
+ *
+ * Returns true if any entry was rewritten.
+ */
+function rewriteLegacyManagedNodeHookCommands(settings, absoluteRunner) {
+  if (!settings || !settings.hooks || !absoluteRunner) return false;
+  const MANAGED_HOOK_FILES = new Set([
+    'gsd-check-update.js',
+    'gsd-statusline.js',
+    'gsd-context-monitor.js',
+    'gsd-prompt-guard.js',
+    'gsd-read-guard.js',
+    'gsd-read-injection-scanner.js',
+    'gsd-workflow-guard.js',
+  ]);
+  let changed = false;
+  for (const entries of Object.values(settings.hooks)) {
+    if (!Array.isArray(entries)) continue;
+    for (const entry of entries) {
+      if (!entry || !Array.isArray(entry.hooks)) continue;
+      for (const h of entry.hooks) {
+        if (!h || typeof h.command !== 'string') continue;
+        const trimmed = h.command.trim();
+        // Match the EXACT legacy form: `node <script>` with optional quoting.
+        // The previous shape used `trimmed.includes(<filename>)` which would
+        // false-positive on user-authored hooks whose path merely contained
+        // a managed filename as a substring (e.g.
+        // /home/me/scripts/wraps-gsd-check-update.js-and-more.js). #3002 CR.
+        const m = trimmed.match(/^node\s+("([^"]+)"|'([^']+)'|(\S+))\s*$/);
+        if (!m) continue;
+        const scriptToken = m[1];
+        const scriptPath = m[2] || m[3] || m[4] || '';
+        // Take the basename — match against MANAGED_HOOK_FILES by exact
+        // equality, not substring containment. Handles both forward and
+        // backslash separators (Windows).
+        const scriptBase = scriptPath.split(/[\\/]/).pop() || '';
+        if (!MANAGED_HOOK_FILES.has(scriptBase)) continue;
+        h.command = `${absoluteRunner} ${scriptToken}`;
+        changed = true;
+      }
+    }
+  }
+  return changed;
+}
+
 /**
  * Build a hook command path using forward slashes for cross-platform compatibility.
  * On Windows, $HOME is not expanded by cmd.exe/PowerShell, so we use the actual path.
@@ -538,7 +614,16 @@ function computePathPrefix({ isGlobal, isOpencode, isWindowsHost: _isWindowsHost
  */
 function buildHookCommand(configDir, hookName, opts) {
   if (!opts) opts = {};
-  const runner = hookName.endsWith('.sh') ? 'bash' : 'node';
+  // .sh hooks run under /bin/bash (POSIX std PATH always includes /bin),
+  // so bare `bash` is fine. .js hooks need the absolute node path because
+  // GUI-launched runtimes start with a minimal PATH that does not include
+  // nvm/Homebrew/Volta-installed node binaries (#2979).
+  const nodeRunner = resolveNodeRunner();
+  const runner = hookName.endsWith('.sh') ? 'bash' : nodeRunner;
+  // resolveNodeRunner returns null when process.execPath is unavailable.
+  // Fall through with null so callers can skip registration with a warning
+  // instead of emitting bare `node` (which would recreate the #2979 bug).
+  if (runner === null) return null;
 
   if (opts.portableHooks) {
     // Replace the home directory prefix with $HOME so the path works when
@@ -7977,6 +8062,14 @@ function install(isGlobal, runtime = 'claude') {
     return;
   }
   const settings = validateHookFields(cleanupOrphanedHooks(rawSettings));
+  // #3002 CR: rewrite legacy `node .../gsd-*.js` command strings carried over
+  // from pre-#2979 installs to use the absolute node binary path. Without this,
+  // existing managed hook entries stay bare-`node`-prefixed across reinstalls
+  // and remain broken under GUI/minimal-PATH runtimes.
+  const settingsRunner = resolveNodeRunner();
+  if (settingsRunner && rewriteLegacyManagedNodeHookCommands(settings, settingsRunner)) {
+    console.log(`  ${green}✓${reset} Rewrote legacy bare-node managed-hook commands to absolute path (#2979)`);
+  }
   // Local installs anchor hook paths so they resolve regardless of cwd (#1906).
   // Claude Code sets $CLAUDE_PROJECT_DIR; Gemini/Antigravity do not — and on
   // Windows their own substitution logic doubles the path (#2557). Those runtimes
@@ -7985,24 +8078,50 @@ function install(isGlobal, runtime = 'claude') {
     ? dirName
     : '"$CLAUDE_PROJECT_DIR"/' + dirName;
   const hookOpts = { portableHooks: hasPortableHooks };
+  // #2979: local-install hook commands also use the absolute node path so
+  // GUI/minimal-PATH runtimes can resolve them. Bare `node` fails when the
+  // host launches the runtime with a stripped PATH (Finder/Antigravity/etc).
+  const localNodeRunner = resolveNodeRunner();
+  // If we cannot resolve an absolute node path AND this is a local install,
+  // skip managed-hook registration. Returning null from buildHookCommand on
+  // global installs has the same effect. Better to skip than to emit a bare
+  // `node` command that recreates the #2979 failure.
+  const localCmd = (hookFile) => localNodeRunner === null
+    ? null
+    : localNodeRunner + ' ' + localPrefix + '/hooks/' + hookFile;
   const statuslineCommand = isGlobal
     ? buildHookCommand(targetDir, 'gsd-statusline.js', hookOpts)
-    : 'node ' + localPrefix + '/hooks/gsd-statusline.js';
+    : localCmd('gsd-statusline.js');
   const updateCheckCommand = isGlobal
     ? buildHookCommand(targetDir, 'gsd-check-update.js', hookOpts)
-    : 'node ' + localPrefix + '/hooks/gsd-check-update.js';
+    : localCmd('gsd-check-update.js');
   const contextMonitorCommand = isGlobal
     ? buildHookCommand(targetDir, 'gsd-context-monitor.js', hookOpts)
-    : 'node ' + localPrefix + '/hooks/gsd-context-monitor.js';
+    : localCmd('gsd-context-monitor.js');
   const promptGuardCommand = isGlobal
     ? buildHookCommand(targetDir, 'gsd-prompt-guard.js', hookOpts)
-    : 'node ' + localPrefix + '/hooks/gsd-prompt-guard.js';
+    : localCmd('gsd-prompt-guard.js');
   const readGuardCommand = isGlobal
     ? buildHookCommand(targetDir, 'gsd-read-guard.js', hookOpts)
-    : 'node ' + localPrefix + '/hooks/gsd-read-guard.js';
+    : localCmd('gsd-read-guard.js');
   const readInjectionScannerCommand = isGlobal
     ? buildHookCommand(targetDir, 'gsd-read-injection-scanner.js', hookOpts)
-    : 'node ' + localPrefix + '/hooks/gsd-read-injection-scanner.js';
+    : localCmd('gsd-read-injection-scanner.js');
+
+  // #3002 CR: when resolveNodeRunner() returns null, every dependent JS-hook
+  // command is null too. Emit one warning here so the operator sees the cause
+  // ONCE instead of per-hook. Each registration site below also guards on its
+  // own *Command variable being truthy, so we never write `command: null`
+  // entries to settings.json (which the runtime's hook schema would reject).
+  const anyJsHookCommandNull = !statuslineCommand
+    || !updateCheckCommand
+    || !contextMonitorCommand
+    || !promptGuardCommand
+    || !readGuardCommand
+    || !readInjectionScannerCommand;
+  if (anyJsHookCommandNull) {
+    console.warn(`  ${yellow}⚠${reset}  Skipping managed JS hook registration — Node executable path unavailable (process.execPath is empty). See #2979 / #3002.`);
+  }
 
   // Enable experimental agents for Gemini CLI (required for custom sub-agents)
   if (isGemini) {
@@ -8033,7 +8152,7 @@ function install(isGlobal, runtime = 'claude') {
     // copy step produces no files but the registration step ran unconditionally,
     // causing "hook error" on every tool invocation.
     const checkUpdateFile = path.join(targetDir, 'hooks', 'gsd-check-update.js');
-    if (!hasGsdUpdateHook && fs.existsSync(checkUpdateFile)) {
+    if (!hasGsdUpdateHook && fs.existsSync(checkUpdateFile) && updateCheckCommand) {
       settings.hooks.SessionStart.push({
         hooks: [
           {
@@ -8057,7 +8176,7 @@ function install(isGlobal, runtime = 'claude') {
     );
 
     const contextMonitorFile = path.join(targetDir, 'hooks', 'gsd-context-monitor.js');
-    if (!hasContextMonitorHook && fs.existsSync(contextMonitorFile)) {
+    if (!hasContextMonitorHook && fs.existsSync(contextMonitorFile) && contextMonitorCommand) {
       settings.hooks[postToolEvent].push({
         matcher: 'Bash|Edit|Write|MultiEdit|Agent|Task',
         hooks: [
@@ -8105,7 +8224,7 @@ function install(isGlobal, runtime = 'claude') {
     );
 
     const promptGuardFile = path.join(targetDir, 'hooks', 'gsd-prompt-guard.js');
-    if (!hasPromptGuardHook && fs.existsSync(promptGuardFile)) {
+    if (!hasPromptGuardHook && fs.existsSync(promptGuardFile) && promptGuardCommand) {
       settings.hooks[preToolEvent].push({
         matcher: 'Write|Edit',
         hooks: [
@@ -8129,7 +8248,7 @@ function install(isGlobal, runtime = 'claude') {
     );
 
     const readGuardFile = path.join(targetDir, 'hooks', 'gsd-read-guard.js');
-    if (!hasReadGuardHook && fs.existsSync(readGuardFile)) {
+    if (!hasReadGuardHook && fs.existsSync(readGuardFile) && readGuardCommand) {
       settings.hooks[preToolEvent].push({
         matcher: 'Write|Edit',
         hooks: [
@@ -8153,7 +8272,7 @@ function install(isGlobal, runtime = 'claude') {
     );
 
     const readInjectionScannerFile = path.join(targetDir, 'hooks', 'gsd-read-injection-scanner.js');
-    if (!hasReadInjectionScannerHook && fs.existsSync(readInjectionScannerFile)) {
+    if (!hasReadInjectionScannerHook && fs.existsSync(readInjectionScannerFile) && readInjectionScannerCommand) {
       settings.hooks[postToolEvent].push({
         matcher: 'Read',
         hooks: [
@@ -8179,13 +8298,13 @@ function install(isGlobal, runtime = 'claude') {
     // /gsd-quick or /gsd-fast for state-tracked changes. Advisory only.
     const workflowGuardCommand = isGlobal
       ? buildHookCommand(targetDir, 'gsd-workflow-guard.js', hookOpts)
-      : 'node ' + localPrefix + '/hooks/gsd-workflow-guard.js';
+      : localCmd('gsd-workflow-guard.js');
     const hasWorkflowGuardHook = settings.hooks[preToolEvent].some(entry =>
       entry.hooks && entry.hooks.some(h => h.command && h.command.includes('gsd-workflow-guard'))
     );
 
     const workflowGuardFile = path.join(targetDir, 'hooks', 'gsd-workflow-guard.js');
-    if (!hasWorkflowGuardHook && fs.existsSync(workflowGuardFile)) {
+    if (!hasWorkflowGuardHook && fs.existsSync(workflowGuardFile) && workflowGuardCommand) {
       settings.hooks[preToolEvent].push({
         matcher: 'Write|Edit',
         hooks: [
@@ -8298,6 +8417,11 @@ function finishInstall(settingsPath, settings, statuslineCommand, shouldInstallS
       // any profile-level statusLine the user has configured (#2248).
       // Pass --force-statusline to override this guard.
       console.log(`  ${yellow}⚠${reset} Skipping statusLine for local install (avoids overriding profile-level settings; use --force-statusline to override)`);
+    } else if (!statuslineCommand) {
+      // #3002 CR: don't write { type: 'command', command: null } — the
+      // runtime's settings schema rejects null commands and the failure
+      // surfaces as a confusing parse error rather than a usable diagnostic.
+      console.warn(`  ${yellow}⚠${reset}  Skipped statusline registration — Node executable path unavailable (process.execPath is empty). See #2979 / #3002.`);
     } else {
       settings.statusLine = {
         type: 'command',
@@ -8307,9 +8431,15 @@ function finishInstall(settingsPath, settings, statuslineCommand, shouldInstallS
     }
   }
 
-  // Write settings when runtime supports settings.json
+  // Write settings when runtime supports settings.json.
+  // #3002 CR: defense-in-depth — re-run validateHookFields right before
+  // serialization. The push-site guards above already skip null-command
+  // entries, but a future regression that bypasses them would still produce
+  // {type: 'command', command: null} items that the runtime hook schema
+  // rejects at parse time. validateHookFields filters those out so the file
+  // we write is always schema-valid.
   if (!isCodex && !isCopilot && !isKilo && !isCursor && !isWindsurf && !isTrae && !isCline) {
-    writeSettings(settingsPath, settings);
+    writeSettings(settingsPath, validateHookFields(settings));
   }
 
   // Configure OpenCode permissions
@@ -9307,6 +9437,9 @@ if (process.env.GSD_TEST_MODE) {
     allRuntimes,
     parseRuntimeInput,
     buildRuntimePromptText,
+    buildHookCommand,
+    resolveNodeRunner,
+    rewriteLegacyManagedNodeHookCommands,
   };
 } else {
 
diff --git a/tests/bug-2979-hook-absolute-node.test.cjs b/tests/bug-2979-hook-absolute-node.test.cjs
new file mode 100644
index 000000000..780c5c71f
--- /dev/null
+++ b/tests/bug-2979-hook-absolute-node.test.cjs
@@ -0,0 +1,385 @@
+'use strict';
+
+process.env.GSD_TEST_MODE = '1';
+
+/**
+ * Bug #2979: Managed JS hooks fail in GUI/minimal-PATH runtimes because
+ * the installer emits bare `node`.
+ *
+ * Reporter evidence: in a stripped PATH like /usr/bin:/bin:/usr/sbin:/sbin
+ * (the default for Finder-launched/Antigravity-spawned processes on macOS),
+ * `node` is not resolvable. Hook commands like
+ *   `node "<HOME>/.gemini/hooks/gsd-check-update.js"`
+ * fail with `/bin/sh: node: command not found` (exit 127).
+ *
+ * Fix: emit the absolute node path (`process.execPath`, the binary
+ * running the installer itself) as the runner. Forward-slash-normalized
+ * and double-quoted so it works on POSIX and Windows.
+ *
+ * This test exercises the public buildHookCommand surface plus the
+ * resolveNodeRunner helper, asserting on structured records:
+ *  - the runner field is an absolute path (not bare 'node')
+ *  - it ends with /node or \\node (or .exe on Windows simulation)
+ *  - .sh hooks still use bare 'bash' (POSIX std PATH always has /bin)
+ *
+ * No source-grep on install.js content — assertions go against the
+ * value returned by the exported function and the parsed structure of
+ * the emitted hook command (split into runner + args).
+ */
+
+const { test, describe } = require('node:test');
+const assert = require('node:assert/strict');
+const path = require('node:path');
+
+const INSTALL = require(path.join(__dirname, '..', 'bin', 'install.js'));
+const { buildHookCommand, resolveNodeRunner } = INSTALL;
+
+/**
+ * Parse a hook command string into { runner, hookPath } structured
+ * record. The shape is `<runner> "<hookPath>"` where <runner> may itself
+ * be a quoted absolute path (containing spaces), so we split on the
+ * trailing quoted-path token rather than the first space.
+ */
+function parseHookCommand(cmd) {
+  // Trailing token: a double-quoted string ending the command.
+  const m = cmd.match(/^(.+?)\s+"([^"]+)"\s*$/);
+  if (!m) {
+    return { runner: null, hookPath: null, raw: cmd };
+  }
+  return { runner: m[1], hookPath: m[2], raw: cmd };
+}
+
+describe('Bug #2979: resolveNodeRunner returns absolute, quoted, forward-slash node path', () => {
+  test('exported as a function', () => {
+    assert.equal(typeof resolveNodeRunner, 'function');
+  });
+
+  test('returns a double-quoted absolute path', () => {
+    const runner = resolveNodeRunner();
+    assert.ok(runner.startsWith('"'), `expected leading double-quote, got: ${runner}`);
+    assert.ok(runner.endsWith('"'), `expected trailing double-quote, got: ${runner}`);
+    const inner = runner.slice(1, -1);
+    assert.ok(path.isAbsolute(inner.replace(/\//g, path.sep)), `expected absolute path, got: ${inner}`);
+  });
+
+  test('uses forward slashes (Windows-safe, matches buildHookCommand convention)', () => {
+    const runner = resolveNodeRunner();
+    assert.ok(!runner.includes('\\'), `expected forward slashes, got: ${runner}`);
+  });
+
+  test('points at a node binary (basename starts with "node")', () => {
+    const runner = resolveNodeRunner();
+    const inner = runner.slice(1, -1);
+    const base = path.posix.basename(inner);
+    assert.ok(/^node(\.exe)?$/i.test(base), `expected basename node or node.exe, got: ${base}`);
+  });
+});
+
+describe('Bug #2979: buildHookCommand for .js hooks emits absolute node runner', () => {
+  test('global install: .js hook uses absolute node path, not bare "node"', () => {
+    const cmd = buildHookCommand('/tmp/.claude', 'gsd-check-update.js');
+    const parsed = parseHookCommand(cmd);
+    assert.notEqual(parsed.runner, null, `failed to parse: ${cmd}`);
+    assert.notEqual(parsed.runner, 'node', `must not emit bare node (#2979): ${cmd}`);
+    // The runner should be a quoted absolute path.
+    assert.ok(parsed.runner.startsWith('"') && parsed.runner.endsWith('"'),
+      `runner must be quoted absolute path, got: ${parsed.runner}`);
+  });
+
+  test('global install: .js hook command parses with hookPath at expected location', () => {
+    const cmd = buildHookCommand('/tmp/.gemini', 'gsd-statusline.js');
+    const parsed = parseHookCommand(cmd);
+    assert.equal(parsed.hookPath, '/tmp/.gemini/hooks/gsd-statusline.js');
+  });
+
+  test('portableHooks global install: .js hook still uses absolute node (only the path is $HOME-relative)', () => {
+    const home = require('node:os').homedir().replace(/\\/g, '/');
+    const configDir = home + '/.gemini';
+    const cmd = buildHookCommand(configDir, 'gsd-check-update.js', { portableHooks: true });
+    const parsed = parseHookCommand(cmd);
+    assert.notEqual(parsed.runner, 'node', `portableHooks must also use absolute node (#2979): ${cmd}`);
+    assert.equal(parsed.hookPath, '$HOME/.gemini/hooks/gsd-check-update.js');
+  });
+});
+
+describe('Bug #2979: buildHookCommand for .sh hooks still uses bare "bash" (POSIX std PATH always has /bin)', () => {
+  test('.sh hook runner is exactly "bash" — bash is in /usr/bin:/bin and resolves under minimal PATH', () => {
+    const cmd = buildHookCommand('/tmp/.claude', 'gsd-session-state.sh');
+    const parsed = parseHookCommand(cmd);
+    assert.equal(parsed.runner, 'bash');
+  });
+});
+
+// ─── #3002 CR follow-up: legacy-bare-node migration ─────────────────────────
+
+const { rewriteLegacyManagedNodeHookCommands } = INSTALL;
+
+describe('Bug #2979 (#3002 CR): rewriteLegacyManagedNodeHookCommands rewrites bare-node managed hooks on reinstall', () => {
+  test('exported as a function', () => {
+    assert.equal(typeof rewriteLegacyManagedNodeHookCommands, 'function');
+  });
+
+  test('rewrites a managed hook entry that uses bare `node ` to the absolute runner', () => {
+    const settings = {
+      hooks: {
+        SessionStart: [{
+          hooks: [
+            { type: 'command', command: 'node "/Users/x/.gemini/hooks/gsd-check-update.js"' },
+          ],
+        }],
+      },
+    };
+    const runner = '"/usr/local/bin/node"';
+    const changed = rewriteLegacyManagedNodeHookCommands(settings, runner);
+    assert.equal(changed, true);
+    assert.equal(
+      settings.hooks.SessionStart[0].hooks[0].command,
+      '"/usr/local/bin/node" "/Users/x/.gemini/hooks/gsd-check-update.js"',
+    );
+  });
+
+  test('does NOT touch entries that already use a quoted absolute runner', () => {
+    const settings = {
+      hooks: {
+        SessionStart: [{
+          hooks: [{ type: 'command', command: '"/usr/local/bin/node" "/x/hooks/gsd-statusline.js"' }],
+        }],
+      },
+    };
+    const runner = '"/usr/local/bin/node"';
+    const before = settings.hooks.SessionStart[0].hooks[0].command;
+    const changed = rewriteLegacyManagedNodeHookCommands(settings, runner);
+    assert.equal(changed, false);
+    assert.equal(settings.hooks.SessionStart[0].hooks[0].command, before);
+  });
+
+  test('does NOT touch user-authored bare-node hooks (filename not in managed allowlist)', () => {
+    const settings = {
+      hooks: {
+        SessionStart: [{
+          hooks: [{ type: 'command', command: 'node /home/me/my-custom-hook.js' }],
+        }],
+      },
+    };
+    const runner = '"/usr/local/bin/node"';
+    const before = settings.hooks.SessionStart[0].hooks[0].command;
+    const changed = rewriteLegacyManagedNodeHookCommands(settings, runner);
+    assert.equal(changed, false);
+    assert.equal(settings.hooks.SessionStart[0].hooks[0].command, before);
+  });
+
+  test('does NOT touch .sh hooks (they correctly use bare bash)', () => {
+    const settings = {
+      hooks: {
+        SessionStart: [{
+          hooks: [{ type: 'command', command: 'bash "/x/hooks/gsd-session-state.sh"' }],
+        }],
+      },
+    };
+    const runner = '"/usr/local/bin/node"';
+    const changed = rewriteLegacyManagedNodeHookCommands(settings, runner);
+    assert.equal(changed, false);
+  });
+
+  test('is a no-op when absoluteRunner is null (resolveNodeRunner failed)', () => {
+    const settings = {
+      hooks: {
+        SessionStart: [{
+          hooks: [{ type: 'command', command: 'node "/x/hooks/gsd-check-update.js"' }],
+        }],
+      },
+    };
+    const before = settings.hooks.SessionStart[0].hooks[0].command;
+    const changed = rewriteLegacyManagedNodeHookCommands(settings, null);
+    assert.equal(changed, false);
+    assert.equal(settings.hooks.SessionStart[0].hooks[0].command, before);
+  });
+
+  // #3002 CR: substring containment was a false-positive vector.
+  // User-authored hooks whose path happened to CONTAIN a managed filename
+  // as a substring would get unconditionally rewritten with the GSD runner.
+  // The fix matches by basename equality.
+  test('does NOT rewrite a user hook whose path contains a managed filename as a substring', () => {
+    const settings = {
+      hooks: {
+        SessionStart: [{
+          hooks: [{
+            type: 'command',
+            // Path contains gsd-check-update.js as substring of a longer
+            // filename, but is NOT actually that file.
+            command: 'node /home/me/scripts/wraps-gsd-check-update.js-helper.js',
+          }],
+        }],
+      },
+    };
+    const runner = '"/usr/local/bin/node"';
+    const before = settings.hooks.SessionStart[0].hooks[0].command;
+    const changed = rewriteLegacyManagedNodeHookCommands(settings, runner);
+    assert.equal(changed, false, 'must not rewrite user hooks with managed-filename-as-substring paths');
+    assert.equal(settings.hooks.SessionStart[0].hooks[0].command, before);
+  });
+
+  test('rewrites a managed entry whose path is quoted with single quotes', () => {
+    const settings = {
+      hooks: {
+        SessionStart: [{
+          hooks: [{ type: 'command', command: "node '/x/hooks/gsd-statusline.js'" }],
+        }],
+      },
+    };
+    const runner = '"/usr/local/bin/node"';
+    const changed = rewriteLegacyManagedNodeHookCommands(settings, runner);
+    assert.equal(changed, true);
+    assert.equal(
+      settings.hooks.SessionStart[0].hooks[0].command,
+      `"/usr/local/bin/node" '/x/hooks/gsd-statusline.js'`,
+    );
+  });
+
+  test('rewrites a managed entry with no path quoting (bareword)', () => {
+    const settings = {
+      hooks: {
+        SessionStart: [{
+          hooks: [{ type: 'command', command: 'node /x/hooks/gsd-context-monitor.js' }],
+        }],
+      },
+    };
+    const runner = '"/usr/local/bin/node"';
+    const changed = rewriteLegacyManagedNodeHookCommands(settings, runner);
+    assert.equal(changed, true);
+    assert.equal(
+      settings.hooks.SessionStart[0].hooks[0].command,
+      '"/usr/local/bin/node" /x/hooks/gsd-context-monitor.js',
+    );
+  });
+
+  test('handles Windows-style backslash path separators when extracting basename', () => {
+    const settings = {
+      hooks: {
+        SessionStart: [{
+          hooks: [{ type: 'command', command: 'node "C:\\\\Users\\\\me\\\\.claude\\\\hooks\\\\gsd-prompt-guard.js"' }],
+        }],
+      },
+    };
+    const runner = '"/usr/local/bin/node"';
+    const changed = rewriteLegacyManagedNodeHookCommands(settings, runner);
+    assert.equal(changed, true);
+  });
+});
+
+describe('Bug #2979 (#3002 CR): resolveNodeRunner returns null when execPath unavailable', () => {
+  test('returns null instead of bare "node" when process.execPath is empty', () => {
+    const orig = process.execPath;
+    try {
+      Object.defineProperty(process, 'execPath', { value: '', configurable: true });
+      const r = resolveNodeRunner();
+      assert.equal(r, null, 'expected null, not bare "node"');
+    } finally {
+      Object.defineProperty(process, 'execPath', { value: orig, configurable: true });
+    }
+  });
+
+  test('buildHookCommand returns null when execPath is unavailable (caller skips registration)', () => {
+    const orig = process.execPath;
+    try {
+      Object.defineProperty(process, 'execPath', { value: '', configurable: true });
+      const cmd = buildHookCommand('/tmp/.claude', 'gsd-statusline.js');
+      assert.equal(cmd, null);
+    } finally {
+      Object.defineProperty(process, 'execPath', { value: orig, configurable: true });
+    }
+  });
+});
+
+// ─── #3002 CR follow-up #2: null-command guards in settings.json ──────────
+
+const { validateHookFields } = INSTALL;
+
+describe('Bug #2979 (#3002 CR follow-up): no command:null hook entries survive serialization', () => {
+  // CR feedback: assert structurally on the resulting settings object, not by
+  // grepping bin/install.js source. The push-site guards (each `if` clause's
+  // `&& <command>` token) skip null-command pushes at the source. As a
+  // backstop, install.js now runs validateHookFields(settings) right before
+  // writeSettings; this test exercises that backstop directly.
+  //
+  // Construct a settings object that contains exactly the kind of null-command
+  // entries that the registration code would have written if my push-site
+  // guards regressed. Run validateHookFields on it. Assert the null entries
+  // are gone and the well-formed entries survive.
+
+  function nullCommandEntry(matcher) {
+    const entry = { hooks: [{ type: 'command', command: null }] };
+    if (matcher) entry.matcher = matcher;
+    return entry;
+  }
+  function realCommandEntry(matcher, command) {
+    const entry = { hooks: [{ type: 'command', command }] };
+    if (matcher) entry.matcher = matcher;
+    return entry;
+  }
+
+  const MANAGED_JS_HOOKS = [
+    { event: 'SessionStart',  matcher: undefined,                                       label: 'gsd-check-update.js' },
+    { event: 'PostToolUse',   matcher: 'Bash|Edit|Write|MultiEdit|Agent|Task',          label: 'gsd-context-monitor.js' },
+    { event: 'PreToolUse',    matcher: 'Write|Edit',                                    label: 'gsd-prompt-guard.js' },
+    { event: 'PreToolUse',    matcher: 'Write|Edit',                                    label: 'gsd-read-guard.js' },
+    { event: 'PostToolUse',   matcher: 'Read',                                          label: 'gsd-read-injection-scanner.js' },
+    { event: 'PreToolUse',    matcher: 'Bash|Edit|Write|MultiEdit',                     label: 'gsd-workflow-guard.js' },
+  ];
+
+  for (const { event, matcher, label } of MANAGED_JS_HOOKS) {
+    test(`validateHookFields strips a null-command ${label} entry from settings.hooks.${event}`, () => {
+      const settings = {
+        hooks: {
+          [event]: [
+            nullCommandEntry(matcher),
+            realCommandEntry(matcher, '"/usr/local/bin/node" "/x/hooks/other.js"'),
+          ],
+        },
+      };
+      const out = validateHookFields(settings);
+      const survivors = out.hooks[event] || [];
+      // The well-formed entry must remain.
+      assert.equal(survivors.length, 1, `expected the real-command entry to survive`);
+      // No survivor entry contains a hook with command === null.
+      for (const e of survivors) {
+        for (const h of e.hooks || []) {
+          assert.notEqual(h.command, null, 'no surviving hook should have command:null');
+        }
+      }
+    });
+  }
+
+  test('validateHookFields drops the entry entirely when all its hooks have null commands', () => {
+    const settings = {
+      hooks: {
+        SessionStart: [nullCommandEntry()],
+      },
+    };
+    const out = validateHookFields(settings);
+    // Empty event arrays should be cleaned up (the entire SessionStart key
+    // gets removed when nothing valid remains).
+    assert.ok(
+      !out.hooks.SessionStart || out.hooks.SessionStart.length === 0,
+      'expected SessionStart to be empty/removed after the only entry was dropped',
+    );
+  });
+
+  test('validateHookFields preserves agent-type hooks while stripping command:null sibling hooks', () => {
+    const settings = {
+      hooks: {
+        SessionStart: [{
+          hooks: [
+            { type: 'command', command: null },
+            { type: 'agent', prompt: 'analyze the session' },
+            { type: 'command', command: '"/usr/local/bin/node" "/x/hooks/y.js"' },
+          ],
+        }],
+      },
+    };
+    const out = validateHookFields(settings);
+    const survivors = out.hooks.SessionStart[0].hooks;
+    assert.equal(survivors.length, 2, 'expected 2 of 3 hooks to survive (the null-command one is stripped)');
+    assert.equal(survivors.find(h => h.command === null), undefined, 'no surviving hook should have command:null');
+  });
+});