diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8d0704cce..c0b45d640 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,9 @@ Format follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
 ## [Unreleased]
 
+### Fixed
+- **Shell hooks falsely flagged as stale on every session** — `gsd-phase-boundary.sh`, `gsd-session-state.sh`, and `gsd-validate-commit.sh` now ship with a `# gsd-hook-version: {{GSD_VERSION}}` header; the installer substitutes `{{GSD_VERSION}}` in `.sh` hooks the same way it does for `.js` hooks; and the stale-hook detector in `gsd-check-update.js` now matches bash `#` comment syntax in addition to JS `//` syntax. All three changes are required together — neither the regex fix alone nor the install fix alone is sufficient to resolve the false positive (#2136, #2206, #2209, #2210, #2212)
+
 ## [1.36.0] - 2026-04-14
 
 ### Added
diff --git a/bin/install.js b/bin/install.js
index 710270024..39520c70e 100755
--- a/bin/install.js
+++ b/bin/install.js
@@ -5761,10 +5761,15 @@ function install(isGlobal, runtime = 'claude') {
             // Ensure hook files are executable (fixes #1162 — missing +x permission)
             try { fs.chmodSync(destFile, 0o755); } catch (e) { /* Windows doesn't support chmod */ }
           } else {
-            fs.copyFileSync(srcFile, destFile);
-            // Ensure .sh hook files are executable (mirrors chmod in build-hooks.js)
+            // .sh hooks carry a gsd-hook-version header so gsd-check-update.js can
+            // detect staleness after updates — stamp the version just like .js hooks.
             if (entry.endsWith('.sh')) {
+              let content = fs.readFileSync(srcFile, 'utf8');
+              content = content.replace(/\{\{GSD_VERSION\}\}/g, pkg.version);
+              fs.writeFileSync(destFile, content);
               try { fs.chmodSync(destFile, 0o755); } catch (e) { /* Windows doesn't support chmod */ }
+            } else {
+              fs.copyFileSync(srcFile, destFile);
             }
           }
         }
@@ -5876,9 +5881,13 @@ function install(isGlobal, runtime = 'claude') {
           fs.writeFileSync(destFile, content);
           try { fs.chmodSync(destFile, 0o755); } catch (e) { /* Windows */ }
         } else {
-          fs.copyFileSync(srcFile, destFile);
           if (entry.endsWith('.sh')) {
+            let content = fs.readFileSync(srcFile, 'utf8');
+            content = content.replace(/\{\{GSD_VERSION\}\}/g, pkg.version);
+            fs.writeFileSync(destFile, content);
             try { fs.chmodSync(destFile, 0o755); } catch (e) { /* Windows */ }
+          } else {
+            fs.copyFileSync(srcFile, destFile);
           }
         }
       }
diff --git a/hooks/gsd-check-update-worker.js b/hooks/gsd-check-update-worker.js
new file mode 100644
index 000000000..92847b93e
--- /dev/null
+++ b/hooks/gsd-check-update-worker.js
@@ -0,0 +1,107 @@
+#!/usr/bin/env node
+// gsd-hook-version: {{GSD_VERSION}}
+// Background worker spawned by gsd-check-update.js (SessionStart hook).
+// Checks for GSD updates and stale hooks, writes result to cache file.
+// Receives paths via environment variables set by the parent hook.
+//
+// Using a separate file (rather than node -e '<inline code>') avoids the
+// template-literal regex-escaping problem: regex source is plain JS here.
+
+'use strict';
+
+const fs = require('fs');
+const path = require('path');
+const { execFileSync } = require('child_process');
+
+const cacheFile = process.env.GSD_CACHE_FILE;
+const projectVersionFile = process.env.GSD_PROJECT_VERSION_FILE;
+const globalVersionFile = process.env.GSD_GLOBAL_VERSION_FILE;
+
+// Compare semver: true if a > b (a is strictly newer than b)
+// Strips pre-release suffixes (e.g. '3-beta.1' → '3') to avoid NaN from Number()
+function isNewer(a, b) {
+  const pa = (a || '').split('.').map(s => Number(s.replace(/-.*/, '')) || 0);
+  const pb = (b || '').split('.').map(s => Number(s.replace(/-.*/, '')) || 0);
+  for (let i = 0; i < 3; i++) {
+    if (pa[i] > pb[i]) return true;
+    if (pa[i] < pb[i]) return false;
+  }
+  return false;
+}
+
+// Check project directory first (local install), then global
+let installed = '0.0.0';
+let configDir = '';
+try {
+  if (fs.existsSync(projectVersionFile)) {
+    installed = fs.readFileSync(projectVersionFile, 'utf8').trim();
+    configDir = path.dirname(path.dirname(projectVersionFile));
+  } else if (fs.existsSync(globalVersionFile)) {
+    installed = fs.readFileSync(globalVersionFile, 'utf8').trim();
+    configDir = path.dirname(path.dirname(globalVersionFile));
+  }
+} catch (e) {}
+
+// Check for stale hooks — compare hook version headers against installed VERSION
+// Hooks are installed at configDir/hooks/ (e.g. ~/.claude/hooks/) (#1421)
+// Only check hooks that GSD currently ships — orphaned files from removed features
+// (e.g., gsd-intel-*.js) must be ignored to avoid permanent stale warnings (#1750)
+const MANAGED_HOOKS = [
+  'gsd-check-update-worker.js',
+  'gsd-check-update.js',
+  'gsd-context-monitor.js',
+  'gsd-phase-boundary.sh',
+  'gsd-prompt-guard.js',
+  'gsd-read-guard.js',
+  'gsd-session-state.sh',
+  'gsd-statusline.js',
+  'gsd-validate-commit.sh',
+  'gsd-workflow-guard.js',
+];
+
+let staleHooks = [];
+if (configDir) {
+  const hooksDir = path.join(configDir, 'hooks');
+  try {
+    if (fs.existsSync(hooksDir)) {
+      const hookFiles = fs.readdirSync(hooksDir).filter(f => MANAGED_HOOKS.includes(f));
+      for (const hookFile of hookFiles) {
+        try {
+          const content = fs.readFileSync(path.join(hooksDir, hookFile), 'utf8');
+          // Match both JS (//) and bash (#) comment styles
+          const versionMatch = content.match(/(?:\/\/|#) gsd-hook-version:\s*(.+)/);
+          if (versionMatch) {
+            const hookVersion = versionMatch[1].trim();
+            if (isNewer(installed, hookVersion) && !hookVersion.includes('{{')) {
+              staleHooks.push({ file: hookFile, hookVersion, installedVersion: installed });
+            }
+          } else {
+            // No version header at all — definitely stale (pre-version-tracking)
+            staleHooks.push({ file: hookFile, hookVersion: 'unknown', installedVersion: installed });
+          }
+        } catch (e) {}
+      }
+    }
+  } catch (e) {}
+}
+
+let latest = null;
+try {
+  latest = execFileSync('npm', ['view', 'get-shit-done-cc', 'version'], {
+    encoding: 'utf8',
+    timeout: 10000,
+    windowsHide: true,
+  }).trim();
+} catch (e) {}
+
+const result = {
+  update_available: latest && isNewer(latest, installed),
+  installed,
+  latest: latest || 'unknown',
+  checked: Math.floor(Date.now() / 1000),
+  stale_hooks: staleHooks.length > 0 ? staleHooks : undefined,
+};
+
+if (cacheFile) {
+  try { fs.writeFileSync(cacheFile, JSON.stringify(result)); } catch (e) {}
+}
diff --git a/hooks/gsd-check-update.js b/hooks/gsd-check-update.js
index 8d0ef9c28..6b400df39 100755
--- a/hooks/gsd-check-update.js
+++ b/hooks/gsd-check-update.js
@@ -44,99 +44,21 @@ if (!fs.existsSync(cacheDir)) {
   fs.mkdirSync(cacheDir, { recursive: true });
 }
 
-// Run check in background (spawn background process, windowsHide prevents console flash)
-const child = spawn(process.execPath, ['-e', `
-  const fs = require('fs');
-  const path = require('path');
-  const { execSync } = require('child_process');
-
-  // Compare semver: true if a > b (a is strictly newer than b)
-  // Strips pre-release suffixes (e.g. '3-beta.1' → '3') to avoid NaN from Number()
-  function isNewer(a, b) {
-    const pa = (a || '').split('.').map(s => Number(s.replace(/-.*/, '')) || 0);
-    const pb = (b || '').split('.').map(s => Number(s.replace(/-.*/, '')) || 0);
-    for (let i = 0; i < 3; i++) {
-      if (pa[i] > pb[i]) return true;
-      if (pa[i] < pb[i]) return false;
-    }
-    return false;
-  }
-
-  const cacheFile = ${JSON.stringify(cacheFile)};
-  const projectVersionFile = ${JSON.stringify(projectVersionFile)};
-  const globalVersionFile = ${JSON.stringify(globalVersionFile)};
-
-  // Check project directory first (local install), then global
-  let installed = '0.0.0';
-  let configDir = '';
-  try {
-    if (fs.existsSync(projectVersionFile)) {
-      installed = fs.readFileSync(projectVersionFile, 'utf8').trim();
-      configDir = path.dirname(path.dirname(projectVersionFile));
-    } else if (fs.existsSync(globalVersionFile)) {
-      installed = fs.readFileSync(globalVersionFile, 'utf8').trim();
-      configDir = path.dirname(path.dirname(globalVersionFile));
-    }
-  } catch (e) {}
-
-  // Check for stale hooks — compare hook version headers against installed VERSION
-  // Hooks are installed at configDir/hooks/ (e.g. ~/.claude/hooks/) (#1421)
-  // Only check hooks that GSD currently ships — orphaned files from removed features
-  // (e.g., gsd-intel-*.js) must be ignored to avoid permanent stale warnings (#1750)
-  const MANAGED_HOOKS = [
-    'gsd-check-update.js',
-    'gsd-context-monitor.js',
-    'gsd-phase-boundary.sh',
-    'gsd-prompt-guard.js',
-    'gsd-read-guard.js',
-    'gsd-session-state.sh',
-    'gsd-statusline.js',
-    'gsd-validate-commit.sh',
-    'gsd-workflow-guard.js',
-  ];
-  let staleHooks = [];
-  if (configDir) {
-    const hooksDir = path.join(configDir, 'hooks');
-    try {
-      if (fs.existsSync(hooksDir)) {
-        const hookFiles = fs.readdirSync(hooksDir).filter(f => MANAGED_HOOKS.includes(f));
-        for (const hookFile of hookFiles) {
-          try {
-            const content = fs.readFileSync(path.join(hooksDir, hookFile), 'utf8');
-            const versionMatch = content.match(/\\/\\/ gsd-hook-version:\\s*(.+)/);
-            if (versionMatch) {
-              const hookVersion = versionMatch[1].trim();
-              if (isNewer(installed, hookVersion) && !hookVersion.includes('{{')) {
-                staleHooks.push({ file: hookFile, hookVersion, installedVersion: installed });
-              }
-            } else {
-              // No version header at all — definitely stale (pre-version-tracking)
-              staleHooks.push({ file: hookFile, hookVersion: 'unknown', installedVersion: installed });
-            }
-          } catch (e) {}
-        }
-      }
-    } catch (e) {}
-  }
-
-  let latest = null;
-  try {
-    latest = execSync('npm view get-shit-done-cc version', { encoding: 'utf8', timeout: 10000, windowsHide: true }).trim();
-  } catch (e) {}
-
-  const result = {
-    update_available: latest && isNewer(latest, installed),
-    installed,
-    latest: latest || 'unknown',
-    checked: Math.floor(Date.now() / 1000),
-    stale_hooks: staleHooks.length > 0 ? staleHooks : undefined
-  };
-
-  fs.writeFileSync(cacheFile, JSON.stringify(result));
-`], {
+// Run check in background via a dedicated worker script.
+// Spawning a file (rather than node -e '<inline code>') keeps the worker logic
+// in plain JS with no template-literal regex-escaping concerns, and makes the
+// worker independently testable.
+const workerPath = path.join(__dirname, 'gsd-check-update-worker.js');
+const child = spawn(process.execPath, [workerPath], {
   stdio: 'ignore',
   windowsHide: true,
-  detached: true  // Required on Windows for proper process detachment
+  detached: true,  // Required on Windows for proper process detachment
+  env: {
+    ...process.env,
+    GSD_CACHE_FILE: cacheFile,
+    GSD_PROJECT_VERSION_FILE: projectVersionFile,
+    GSD_GLOBAL_VERSION_FILE: globalVersionFile,
+  },
 });
 
 child.unref();
diff --git a/hooks/gsd-phase-boundary.sh b/hooks/gsd-phase-boundary.sh
index 6b0c39f07..e2e1c5f3d 100755
--- a/hooks/gsd-phase-boundary.sh
+++ b/hooks/gsd-phase-boundary.sh
@@ -1,4 +1,5 @@
 #!/bin/bash
+# gsd-hook-version: {{GSD_VERSION}}
 # gsd-phase-boundary.sh — PostToolUse hook: detect .planning/ file writes
 # Outputs a reminder when planning files are modified outside normal workflow.
 # Uses Node.js for JSON parsing (always available in GSD projects, no jq dependency).
diff --git a/hooks/gsd-session-state.sh b/hooks/gsd-session-state.sh
index 53f70c646..bbe8b9356 100755
--- a/hooks/gsd-session-state.sh
+++ b/hooks/gsd-session-state.sh
@@ -1,4 +1,5 @@
 #!/bin/bash
+# gsd-hook-version: {{GSD_VERSION}}
 # gsd-session-state.sh — SessionStart hook: inject project state reminder
 # Outputs STATE.md head on every session start for orientation.
 #
diff --git a/hooks/gsd-validate-commit.sh b/hooks/gsd-validate-commit.sh
index fd2dd38a5..c7737093e 100755
--- a/hooks/gsd-validate-commit.sh
+++ b/hooks/gsd-validate-commit.sh
@@ -1,4 +1,5 @@
 #!/bin/bash
+# gsd-hook-version: {{GSD_VERSION}}
 # gsd-validate-commit.sh — PreToolUse hook: enforce Conventional Commits format
 # Blocks git commit commands with non-conforming messages (exit 2).
 # Allows conforming messages and all non-commit commands (exit 0).
diff --git a/scripts/build-hooks.js b/scripts/build-hooks.js
index ff19aeba5..a2f136d47 100644
--- a/scripts/build-hooks.js
+++ b/scripts/build-hooks.js
@@ -15,6 +15,7 @@ const DIST_DIR = path.join(HOOKS_DIR, 'dist');
 
 // Hooks to copy (pure Node.js, no bundling needed)
 const HOOKS_TO_COPY = [
+  'gsd-check-update-worker.js',
   'gsd-check-update.js',
   'gsd-context-monitor.js',
   'gsd-prompt-guard.js',
diff --git a/tests/bug-2136-sh-hook-version.test.cjs b/tests/bug-2136-sh-hook-version.test.cjs
new file mode 100644
index 000000000..8d5b8f219
--- /dev/null
+++ b/tests/bug-2136-sh-hook-version.test.cjs
@@ -0,0 +1,359 @@
+/**
+ * Regression tests for bug #2136 / #2206
+ *
+ * Root cause: three bash hooks (gsd-phase-boundary.sh, gsd-session-state.sh,
+ * gsd-validate-commit.sh) shipped without a gsd-hook-version header, and the
+ * stale-hook detector in gsd-check-update.js only matched JavaScript comment
+ * syntax (//) — not bash comment syntax (#).
+ *
+ * Result: every session showed "⚠ stale hooks — run /gsd-update" immediately
+ * after a fresh install, because the detector saw hookVersion: 'unknown' for
+ * all three bash hooks.
+ *
+ * This fix requires THREE parts working in concert:
+ *   1. Bash hooks ship with "# gsd-hook-version: {{GSD_VERSION}}"
+ *   2. install.js substitutes {{GSD_VERSION}} in .sh files at install time
+ *   3. gsd-check-update.js regex matches both "//" and "#" comment styles
+ *
+ * Neither fix alone is sufficient:
+ *   - Headers + regex fix only (no install.js fix): installed hooks contain
+ *     literal "{{GSD_VERSION}}" — the {{-guard silently skips them, making
+ *     bash hook staleness permanently undetectable after future updates.
+ *   - Headers + install.js fix only (no regex fix): installed hooks are
+ *     stamped correctly but the detector still can't read bash "#" comments,
+ *     so they still land in the "unknown / stale" branch on every session.
+ */
+
+'use strict';
+
+// NOTE: Do NOT set GSD_TEST_MODE here — the E2E install tests spawn the
+// real installer subprocess, which skips all install logic when GSD_TEST_MODE=1.
+
+const { describe, test, before, beforeEach, afterEach } = require('node:test');
+const assert = require('node:assert/strict');
+const fs = require('fs');
+const path = require('path');
+const os = require('os');
+const { execFileSync } = require('child_process');
+
+const HOOKS_DIR = path.join(__dirname, '..', 'hooks');
+const CHECK_UPDATE_FILE = path.join(HOOKS_DIR, 'gsd-check-update.js');
+const WORKER_FILE = path.join(HOOKS_DIR, 'gsd-check-update-worker.js');
+const INSTALL_SCRIPT = path.join(__dirname, '..', 'bin', 'install.js');
+const BUILD_SCRIPT = path.join(__dirname, '..', 'scripts', 'build-hooks.js');
+
+const SH_HOOKS = [
+  'gsd-phase-boundary.sh',
+  'gsd-session-state.sh',
+  'gsd-validate-commit.sh',
+];
+
+// ─── Ensure hooks/dist/ is populated before install tests ────────────────────
+
+before(() => {
+  execFileSync(process.execPath, [BUILD_SCRIPT], {
+    encoding: 'utf-8',
+    stdio: 'pipe',
+  });
+});
+
+// ─── Helpers ─────────────────────────────────────────────────────────────────
+
+function createTempDir(prefix) {
+  return fs.mkdtempSync(path.join(os.tmpdir(), prefix));
+}
+
+function cleanup(dir) {
+  try { fs.rmSync(dir, { recursive: true, force: true }); } catch { /* ignore */ }
+}
+
+function runInstaller(configDir) {
+  execFileSync(process.execPath, [INSTALL_SCRIPT, '--claude', '--global', '--yes'], {
+    encoding: 'utf-8',
+    stdio: 'pipe',
+    env: { ...process.env, CLAUDE_CONFIG_DIR: configDir },
+  });
+  return path.join(configDir, 'hooks');
+}
+
+// ─────────────────────────────────────────────────────────────────────────────
+// Part 1: Bash hook sources carry the version header placeholder
+// ─────────────────────────────────────────────────────────────────────────────
+
+describe('bug #2136 part 1: bash hook sources carry gsd-hook-version placeholder', () => {
+  for (const sh of SH_HOOKS) {
+    test(`${sh} contains "# gsd-hook-version: {{GSD_VERSION}}"`, () => {
+      const content = fs.readFileSync(path.join(HOOKS_DIR, sh), 'utf8');
+      assert.ok(
+        content.includes('# gsd-hook-version: {{GSD_VERSION}}'),
+        `${sh} must include "# gsd-hook-version: {{GSD_VERSION}}" so the ` +
+        `installer can stamp it and gsd-check-update.js can detect staleness`
+      );
+    });
+  }
+
+  test('version header is on line 2 (immediately after shebang)', () => {
+    // Placing the header immediately after #!/bin/bash ensures it is always
+    // found regardless of how much of the file is read.
+    for (const sh of SH_HOOKS) {
+      const lines = fs.readFileSync(path.join(HOOKS_DIR, sh), 'utf8').split('\n');
+      assert.strictEqual(lines[0], '#!/bin/bash', `${sh} line 1 must be #!/bin/bash`);
+      assert.ok(
+        lines[1].startsWith('# gsd-hook-version:'),
+        `${sh} line 2 must be the gsd-hook-version header (got: "${lines[1]}")`
+      );
+    }
+  });
+});
+
+// ─────────────────────────────────────────────────────────────────────────────
+// Part 2: gsd-check-update-worker.js regex handles bash "#" comment syntax
+// (Logic moved from inline -e template literal to dedicated worker file)
+// ─────────────────────────────────────────────────────────────────────────────
+
+describe('bug #2136 part 2: stale-hook detector handles bash comment syntax', () => {
+  let src;
+
+  before(() => {
+    src = fs.readFileSync(WORKER_FILE, 'utf8');
+  });
+
+  test('version regex in source matches "#" comment syntax in addition to "//"', () => {
+    // The regex string in the source must contain the alternation for "#".
+    // The worker uses plain JS (no template-literal escaping), so the form is
+    // "(?:\/\/|#)" directly in source.
+    const hasBashAlternative =
+      src.includes('(?:\\/\\/|#)') ||     // escaped form (old template-literal style)
+      src.includes('(?:\/\/|#)');          // direct form in plain JS worker
+    assert.ok(
+      hasBashAlternative,
+      'gsd-check-update-worker.js version regex must include an alternative for bash "#" comments. ' +
+      'Expected to find (?:\\/\\/|#) or (?:\/\/|#) in the source. ' +
+      'The original "//" only regex causes bash hooks to always report hookVersion: "unknown"'
+    );
+  });
+
+  test('version regex does not use the old JS-only form as the sole pattern', () => {
+    // The old regex inside the template literal was the string:
+    //   /\\/\\/ gsd-hook-version:\\s*(.+)/
+    // which, when evaluated in the subprocess, produced: /\/\/ gsd-hook-version:\s*(.+)/
+    // That only matched JS "//" comments — never bash "#".
+    // We verify that the old exact string no longer appears.
+    assert.ok(
+      !src.includes('\\/\\/ gsd-hook-version'),
+      'gsd-check-update-worker.js must not use the old JS-only (\\/\\/ gsd-hook-version) ' +
+      'escape form as the sole version matcher — it cannot match bash "#" comments'
+    );
+  });
+
+  test('version regex correctly matches both bash and JS hook version headers', () => {
+    // Verify that the versionMatch line in the source uses a regex that matches
+    // both bash "#" and JS "//" comment styles. We check the source contains the
+    // expected alternation, then directly test the known required pattern.
+    //
+    // We do NOT try to extract and evaluate the regex from source (it contains ")"
+    // which breaks simple extraction), so instead we confirm the source matches
+    // our expectation and run the regex itself.
+    assert.ok(
+      src.includes('gsd-hook-version'),
+      'gsd-check-update-worker.js must contain a gsd-hook-version version check'
+    );
+
+    // The fixed regex that must be present: matches both comment styles
+    const fixedRegex = /(?:\/\/|#) gsd-hook-version:\s*(.+)/;
+
+    assert.ok(
+      fixedRegex.test('# gsd-hook-version: 1.36.0'),
+      'bash-style "# gsd-hook-version: X" must be matchable by the required regex'
+    );
+    assert.ok(
+      fixedRegex.test('// gsd-hook-version: 1.36.0'),
+      'JS-style "// gsd-hook-version: X" must still match (no regression)'
+    );
+    assert.ok(
+      !fixedRegex.test('gsd-hook-version: 1.36.0'),
+      'line without a comment prefix must not match (prevents false positives)'
+    );
+  });
+});
+
+// ─────────────────────────────────────────────────────────────────────────────
+// Part 3a: install.js bundled path substitutes {{GSD_VERSION}} in .sh hooks
+// ─────────────────────────────────────────────────────────────────────────────
+
+describe('bug #2136 part 3a: install.js bundled path substitutes {{GSD_VERSION}} in .sh hooks', () => {
+  let src;
+
+  before(() => {
+    src = fs.readFileSync(INSTALL_SCRIPT, 'utf8');
+  });
+
+  test('.sh branch in bundled hook copy loop reads file and substitutes GSD_VERSION', () => {
+    // Anchor on configDirReplacement — unique to the bundled-hooks path.
+    const anchorIdx = src.indexOf('configDirReplacement');
+    assert.ok(anchorIdx !== -1, 'bundled hook copy loop anchor (configDirReplacement) not found');
+
+    // Window large enough for the if/else block
+    const region = src.slice(anchorIdx, anchorIdx + 2000);
+
+    assert.ok(
+      region.includes("entry.endsWith('.sh')"),
+      "bundled hook copy loop must check entry.endsWith('.sh')"
+    );
+    assert.ok(
+      region.includes('GSD_VERSION'),
+      'bundled .sh branch must reference GSD_VERSION substitution. Without this, ' +
+      'installed .sh hooks contain the literal "{{GSD_VERSION}}" placeholder and ' +
+      'bash hook staleness becomes permanently undetectable after future updates'
+    );
+    // copyFileSync on a .sh file would skip substitution — ensure we read+write instead
+    const shBranchIdx = region.indexOf("entry.endsWith('.sh')");
+    const shBranchRegion = region.slice(shBranchIdx, shBranchIdx + 400);
+    assert.ok(
+      shBranchRegion.includes('readFileSync') || shBranchRegion.includes('writeFileSync'),
+      'bundled .sh branch must read the file (readFileSync) to perform substitution, ' +
+      'not copyFileSync directly (which skips template expansion)'
+    );
+  });
+});
+
+// ─────────────────────────────────────────────────────────────────────────────
+// Part 3b: install.js Codex path also substitutes {{GSD_VERSION}} in .sh hooks
+// ─────────────────────────────────────────────────────────────────────────────
+
+describe('bug #2136 part 3b: install.js Codex path substitutes {{GSD_VERSION}} in .sh hooks', () => {
+  let src;
+
+  before(() => {
+    src = fs.readFileSync(INSTALL_SCRIPT, 'utf8');
+  });
+
+  test('.sh branch in Codex hook copy block substitutes GSD_VERSION', () => {
+    // Anchor on codexHooksSrc — unique to the Codex path.
+    const anchorIdx = src.indexOf('codexHooksSrc');
+    assert.ok(anchorIdx !== -1, 'Codex hook copy block anchor (codexHooksSrc) not found');
+
+    const region = src.slice(anchorIdx, anchorIdx + 2000);
+
+    assert.ok(
+      region.includes("entry.endsWith('.sh')"),
+      "Codex hook copy block must check entry.endsWith('.sh')"
+    );
+    assert.ok(
+      region.includes('GSD_VERSION'),
+      'Codex .sh branch must substitute {{GSD_VERSION}}. The bundled path was fixed ' +
+      'but Codex installs a separate copy of the hooks from hooks/dist that also needs stamping'
+    );
+  });
+});
+
+// ─────────────────────────────────────────────────────────────────────────────
+// Part 4: End-to-end — installed .sh hooks have stamped version, not placeholder
+// ─────────────────────────────────────────────────────────────────────────────
+
+describe('bug #2136 part 4: installed .sh hooks contain stamped concrete version', () => {
+  let tmpDir;
+
+  beforeEach(() => {
+    tmpDir = createTempDir('gsd-2136-install-');
+  });
+
+  afterEach(() => {
+    cleanup(tmpDir);
+  });
+
+  test('installed .sh hooks contain a concrete version string, not the template placeholder', () => {
+    const hooksDir = runInstaller(tmpDir);
+
+    for (const sh of SH_HOOKS) {
+      const hookPath = path.join(hooksDir, sh);
+      assert.ok(fs.existsSync(hookPath), `${sh} must be installed`);
+
+      const content = fs.readFileSync(hookPath, 'utf8');
+
+      assert.ok(
+        content.includes('# gsd-hook-version:'),
+        `installed ${sh} must contain a "# gsd-hook-version:" header`
+      );
+      assert.ok(
+        !content.includes('{{GSD_VERSION}}'),
+        `installed ${sh} must not contain literal "{{GSD_VERSION}}" — ` +
+        `install.js must substitute it with the concrete package version`
+      );
+
+      const versionMatch = content.match(/# gsd-hook-version:\s*(\S+)/);
+      assert.ok(versionMatch, `installed ${sh} version header must have a version value`);
+      assert.match(
+        versionMatch[1],
+        /^\d+\.\d+\.\d+/,
+        `installed ${sh} version "${versionMatch[1]}" must be a semver-like string`
+      );
+    }
+  });
+
+  test('stale-hook detector reports zero stale bash hooks immediately after fresh install', () => {
+    // This is the definitive end-to-end proof: after install, run the actual
+    // version-check logic (extracted from gsd-check-update.js) against the
+    // installed hooks and verify none are flagged stale.
+    const hooksDir = runInstaller(tmpDir);
+    const pkg = require(path.join(__dirname, '..', 'package.json'));
+    const installedVersion = pkg.version;
+
+    // Build a subprocess that runs the staleness check logic in isolation.
+    // We pass the installed version, hooks dir, and hook filenames as JSON
+    // to avoid any injection risk.
+    const checkScript = `
+      'use strict';
+      const fs = require('fs');
+      const path = require('path');
+
+      function isNewer(a, b) {
+        const pa = (a || '').split('.').map(s => Number(s.replace(/-.*/, '')) || 0);
+        const pb = (b || '').split('.').map(s => Number(s.replace(/-.*/, '')) || 0);
+        for (let i = 0; i < 3; i++) {
+          if (pa[i] > pb[i]) return true;
+          if (pa[i] < pb[i]) return false;
+        }
+        return false;
+      }
+
+      const hooksDir = ${JSON.stringify(hooksDir)};
+      const installed = ${JSON.stringify(installedVersion)};
+      const shHooks = ${JSON.stringify(SH_HOOKS)};
+      // Use the same regex that the fixed gsd-check-update.js uses
+      const versionRe = /(?:\\/\\/|#) gsd-hook-version:\\s*(.+)/;
+
+      const staleHooks = [];
+      for (const hookFile of shHooks) {
+        const hookPath = path.join(hooksDir, hookFile);
+        if (!fs.existsSync(hookPath)) {
+          staleHooks.push({ file: hookFile, hookVersion: 'missing' });
+          continue;
+        }
+        const content = fs.readFileSync(hookPath, 'utf8');
+        const m = content.match(versionRe);
+        if (m) {
+          const hookVersion = m[1].trim();
+          if (isNewer(installed, hookVersion) && !hookVersion.includes('{{')) {
+            staleHooks.push({ file: hookFile, hookVersion, installedVersion: installed });
+          }
+        } else {
+          staleHooks.push({ file: hookFile, hookVersion: 'unknown', installedVersion: installed });
+        }
+      }
+      process.stdout.write(JSON.stringify(staleHooks));
+    `;
+
+    const result = execFileSync(process.execPath, ['-e', checkScript], { encoding: 'utf8' });
+    const staleHooks = JSON.parse(result);
+
+    assert.deepStrictEqual(
+      staleHooks,
+      [],
+      `Fresh install must produce zero stale bash hooks.\n` +
+      `Got: ${JSON.stringify(staleHooks, null, 2)}\n` +
+      `This indicates either the version header was not stamped by install.js, ` +
+      `or the detector regex cannot match bash "#" comment syntax.`
+    );
+  });
+});
diff --git a/tests/core.test.cjs b/tests/core.test.cjs
index 39ba9e2a2..162135355 100644
--- a/tests/core.test.cjs
+++ b/tests/core.test.cjs
@@ -1071,8 +1071,10 @@ describe('stale hook filter', () => {
 
 describe('stale hook path', () => {
   test('gsd-check-update.js checks configDir/hooks/ where hooks are actually installed (#1421)', () => {
+    // The stale-hook scan logic lives in the worker (moved from inline -e template literal).
+    // The worker receives configDir via env and constructs the hooksDir path.
     const content = fs.readFileSync(
-      path.join(__dirname, '..', 'hooks', 'gsd-check-update.js'), 'utf-8'
+      path.join(__dirname, '..', 'hooks', 'gsd-check-update-worker.js'), 'utf-8'
     );
     // Hooks are installed at configDir/hooks/ (e.g. ~/.claude/hooks/),
     // not configDir/get-shit-done/hooks/ which doesn't exist (#1421)
diff --git a/tests/managed-hooks.test.cjs b/tests/managed-hooks.test.cjs
index 5c6912714..21352ee99 100644
--- a/tests/managed-hooks.test.cjs
+++ b/tests/managed-hooks.test.cjs
@@ -18,7 +18,9 @@ const fs = require('fs');
 const path = require('path');
 
 const HOOKS_DIR = path.join(__dirname, '..', 'hooks');
-const CHECK_UPDATE_FILE = path.join(HOOKS_DIR, 'gsd-check-update.js');
+// MANAGED_HOOKS now lives in the worker script (extracted from inline -e code
+// to avoid template-literal regex-escaping concerns). The test reads the worker.
+const MANAGED_HOOKS_FILE = path.join(HOOKS_DIR, 'gsd-check-update-worker.js');
 
 describe('bug #2136: MANAGED_HOOKS must include all shipped hook files', () => {
   let src;
@@ -26,12 +28,12 @@ describe('bug #2136: MANAGED_HOOKS must include all shipped hook files', () => {
   let shippedHooks;
 
   // Read once — all tests share the same source snapshot
-  src = fs.readFileSync(CHECK_UPDATE_FILE, 'utf-8');
+  src = fs.readFileSync(MANAGED_HOOKS_FILE, 'utf-8');
 
   // Extract the MANAGED_HOOKS array entries from the source
   // The array is defined as a multi-line array literal of quoted strings
   const match = src.match(/const MANAGED_HOOKS\s*=\s*\[([\s\S]*?)\]/);
-  assert.ok(match, 'MANAGED_HOOKS array not found in gsd-check-update.js');
+  assert.ok(match, 'MANAGED_HOOKS array not found in gsd-check-update-worker.js');
 
   managedHooks = match[1]
     .split('\n')
@@ -47,7 +49,7 @@ describe('bug #2136: MANAGED_HOOKS must include all shipped hook files', () => {
     for (const hookFile of jsHooks) {
       assert.ok(
         managedHooks.includes(hookFile),
-        `${hookFile} is shipped in hooks/ but missing from MANAGED_HOOKS in gsd-check-update.js`
+        `${hookFile} is shipped in hooks/ but missing from MANAGED_HOOKS in gsd-check-update-worker.js`
       );
     }
   });
@@ -57,7 +59,7 @@ describe('bug #2136: MANAGED_HOOKS must include all shipped hook files', () => {
     for (const hookFile of shHooks) {
       assert.ok(
         managedHooks.includes(hookFile),
-        `${hookFile} is shipped in hooks/ but missing from MANAGED_HOOKS in gsd-check-update.js`
+        `${hookFile} is shipped in hooks/ but missing from MANAGED_HOOKS in gsd-check-update-worker.js`
       );
     }
   });
diff --git a/tests/orphaned-hooks.test.cjs b/tests/orphaned-hooks.test.cjs
index 83d4aff19..b724b9dae 100644
--- a/tests/orphaned-hooks.test.cjs
+++ b/tests/orphaned-hooks.test.cjs
@@ -11,31 +11,41 @@ const assert = require('node:assert/strict');
 const fs = require('fs');
 const path = require('path');
 
+// MANAGED_HOOKS lives in the worker file (extracted from inline -e code to eliminate
+// template-literal regex-escaping concerns). Tests read the worker directly.
 const CHECK_UPDATE_PATH = path.join(__dirname, '..', 'hooks', 'gsd-check-update.js');
+const WORKER_PATH = path.join(__dirname, '..', 'hooks', 'gsd-check-update-worker.js');
 const BUILD_HOOKS_PATH = path.join(__dirname, '..', 'scripts', 'build-hooks.js');
 
 describe('orphaned hooks stale detection (#1750)', () => {
   test('stale hook scanner uses an allowlist of managed hooks, not a wildcard', () => {
-    const content = fs.readFileSync(CHECK_UPDATE_PATH, 'utf8');
+    const content = fs.readFileSync(WORKER_PATH, 'utf8');
 
     // The scanner MUST NOT use a broad `startsWith('gsd-')` filter that catches
     // orphaned files from removed features (gsd-intel-index.js, gsd-intel-prune.js, etc.)
     // Instead, it should reference a known set of managed hook filenames.
-
-    // Extract the spawned child script (everything between the template literal backticks)
-    const childScriptMatch = content.match(/spawn\(process\.execPath,\s*\['-e',\s*`([\s\S]*?)`\]/);
-    assert.ok(childScriptMatch, 'should find the spawned child script');
-    const childScript = childScriptMatch[1];
-
-    // The child script must NOT have a broad gsd-*.js wildcard filter
-    const hasBroadFilter = /readdirSync\([^)]+\)\.filter\([^)]*startsWith\('gsd-'\)\s*&&[^)]*endsWith\('\.js'\)/s.test(childScript);
+    const hasBroadFilter = /readdirSync\([^)]+\)\.filter\([^)]*startsWith\('gsd-'\)\s*&&[^)]*endsWith\('\.js'\)/s.test(content);
     assert.ok(!hasBroadFilter,
       'scanner must NOT use broad startsWith("gsd-") && endsWith(".js") filter — ' +
       'this catches orphaned hooks from removed features (e.g., gsd-intel-index.js). ' +
       'Use a MANAGED_HOOKS allowlist instead.');
   });
 
-  test('managed hooks list in check-update matches build-hooks HOOKS_TO_COPY JS entries', () => {
+  test('gsd-check-update.js spawns the worker by file path (not inline -e code)', () => {
+    // After the worker extraction, the main hook must spawn the worker file
+    // rather than embedding all logic in a template literal.
+    const content = fs.readFileSync(CHECK_UPDATE_PATH, 'utf8');
+    assert.ok(
+      content.includes('gsd-check-update-worker.js'),
+      'gsd-check-update.js must reference gsd-check-update-worker.js as the spawn target'
+    );
+    assert.ok(
+      !content.includes("'-e'"),
+      'gsd-check-update.js must not use node -e inline code (logic moved to worker file)'
+    );
+  });
+
+  test('managed hooks list in worker matches build-hooks HOOKS_TO_COPY JS entries', () => {
     // Extract JS hooks from build-hooks.js HOOKS_TO_COPY
     const buildContent = fs.readFileSync(BUILD_HOOKS_PATH, 'utf8');
     const hooksArrayMatch = buildContent.match(/HOOKS_TO_COPY\s*=\s*\[([\s\S]*?)\]/);
@@ -48,25 +58,18 @@ describe('orphaned hooks stale detection (#1750)', () => {
     }
     assert.ok(jsHooks.length >= 5, `expected at least 5 JS hooks in HOOKS_TO_COPY, got ${jsHooks.length}`);
 
-    // The check-update hook should define its own managed hooks list
-    // that matches the JS entries from HOOKS_TO_COPY
-    const checkContent = fs.readFileSync(CHECK_UPDATE_PATH, 'utf8');
-    const childScriptMatch = checkContent.match(/spawn\(process\.execPath,\s*\['-e',\s*`([\s\S]*?)`\]/);
-    const childScript = childScriptMatch[1];
-
-    // Verify each JS hook from HOOKS_TO_COPY is referenced in the managed list
+    // MANAGED_HOOKS in the worker must include each JS hook from HOOKS_TO_COPY
+    const workerContent = fs.readFileSync(WORKER_PATH, 'utf8');
     for (const hook of jsHooks) {
       assert.ok(
-        childScript.includes(hook),
-        `managed hooks in check-update should include '${hook}' from HOOKS_TO_COPY`
+        workerContent.includes(hook),
+        `MANAGED_HOOKS in worker should include '${hook}' from HOOKS_TO_COPY`
       );
     }
   });
 
-  test('orphaned hook filenames would NOT match the managed hooks list', () => {
-    const checkContent = fs.readFileSync(CHECK_UPDATE_PATH, 'utf8');
-    const childScriptMatch = checkContent.match(/spawn\(process\.execPath,\s*\['-e',\s*`([\s\S]*?)`\]/);
-    const childScript = childScriptMatch[1];
+  test('orphaned hook filenames are NOT in the MANAGED_HOOKS list', () => {
+    const workerContent = fs.readFileSync(WORKER_PATH, 'utf8');
 
     // These are real orphaned hooks from the removed intel feature
     const orphanedHooks = [
@@ -77,8 +80,8 @@ describe('orphaned hooks stale detection (#1750)', () => {
 
     for (const orphan of orphanedHooks) {
       assert.ok(
-        !childScript.includes(orphan),
-        `orphaned hook '${orphan}' must NOT be in the managed hooks list`
+        !workerContent.includes(orphan),
+        `orphaned hook '${orphan}' must NOT be in the MANAGED_HOOKS list`
       );
     }
   });