diff --git a/.changeset/eager-tunas-swim.md b/.changeset/eager-tunas-swim.md
new file mode 100644
index 000000000..5a77fc331
--- /dev/null
+++ b/.changeset/eager-tunas-swim.md
@@ -0,0 +1,5 @@
+---
+type: Fixed
+pr: 1991
+---
+**`/gsd-quick` no longer halts with a stale-base worktree mismatch** — the worktree executor now degrades to sequential execution when its fork base has diverged from origin/HEAD, instead of spawning a worktree guaranteed to fail the base-mismatch guard.
diff --git a/.changeset/steady-ibex-run.md b/.changeset/steady-ibex-run.md
new file mode 100644
index 000000000..bf1b37a3b
--- /dev/null
+++ b/.changeset/steady-ibex-run.md
@@ -0,0 +1,5 @@
+---
+type: Fixed
+pr: 2049
+---
+**Skill-bearing capabilities now surface correctly on flat command-layout installs** — on an install using the flat `commands/gsd-<stem>.md` source layout (e.g. a Claude Code local project install with no `commands/gsd/` subdir), every skill-bearing capability (`nyquist`, `code-review`, `security`, `ui`, `mempalace`, `ai-integration`, `profile-pipeline`) was silently reported `surfaced:false`/`enabled:false`/`active:false`, so their loop hooks (`verify:post`, `execute:post`, etc.) never fired even with the corresponding `workflow.*` toggle on. The skill-manifest resolver now detects the flat layout and produces the same stems the nested `commands/gsd/*.md` loader does. (#1858)
diff --git a/docs/how-to/fix-worktree-base-mismatch.md b/docs/how-to/fix-worktree-base-mismatch.md
index 16b445198..e442d26ff 100644
--- a/docs/how-to/fix-worktree-base-mismatch.md
+++ b/docs/how-to/fix-worktree-base-mismatch.md
@@ -1,16 +1,16 @@
 # How to fix the worktree base-mismatch (exit 42) error
 
-**Goal:** Understand why `/gsd-execute-phase` halts with `FATAL: worktree base mismatch` / exit 42 when your branch is ahead of the default branch, and choose the right fix to restore normal — or parallel — execution.
+**Goal:** Understand why `/gsd-execute-phase` or `/gsd-quick` halts with `FATAL: worktree base mismatch` / exit 42 when your branch is ahead of the default branch, and choose the right fix to restore normal — or parallel — execution.
 
-**Prerequisites:** GSD Core is installed and you have an active project. You have run `/gsd-execute-phase` and either seen the exit-42 error or the one-line `⚠ Worktree base mismatch` warning.
+**Prerequisites:** GSD Core is installed and you have an active project. You have run `/gsd-execute-phase` or `/gsd-quick` and either seen the exit-42 error or the one-line `⚠ Worktree base mismatch` warning.
 
 ---
 
 ## What you will see
 
-When you run `/gsd-execute-phase` on a branch that is ahead of the repository's default branch (for example, an unmerged milestone branch, a long-lived feature branch, or a branch with commits not yet in `origin/HEAD`), you may see one of two messages:
+When you run `/gsd-execute-phase` or `/gsd-quick` on a branch that is ahead of the repository's default branch (for example, an unmerged milestone branch, a long-lived feature branch, or a branch with commits not yet in `origin/HEAD`), you may see one of two messages:
 
-**Automatic-degrade warning (phase still completes):**
+**Automatic-degrade warning (phase or quick task still completes):**
 
 ```
 ⚠ Worktree base mismatch: HEAD (abc12345) differs from origin/HEAD (def67890).
@@ -19,7 +19,7 @@ To keep parallel worktrees, set worktree.baseRef:"head" in
 .claude/settings.local.json (or run: gsd-tools worktree set-baseref). See #683.
 ```
 
-The phase runs to completion sequentially; nothing is blocked. This is the runtime mitigation.
+The phase or quick task runs to completion sequentially; nothing is blocked. This is the runtime mitigation (`/gsd-execute-phase`: #683/#1369; `/gsd-quick`: #1941).
 
 **Exit-42 halt (older installs or misconfigured environments):**
 
diff --git a/gsd-core/workflows/quick.md b/gsd-core/workflows/quick.md
index 40668ff58..fc9f98756 100644
--- a/gsd-core/workflows/quick.md
+++ b/gsd-core/workflows/quick.md
@@ -671,6 +671,26 @@ fi
 
 **Step 6: Spawn executor**
 
+Auto-degrade to sequential if HEAD has diverged from the worktree fork base (#1941, mirrors
+execute-phase's #683/#1369 guard). Claude Code's `isolation="worktree"` forks new worktrees from
+`origin/HEAD`, not the live local HEAD. If a prior quick task in this session (or the Step 5.6
+pre-dispatch plan commit above) advanced local HEAD without an intervening `git push`,
+`origin/HEAD` stays pinned to a stale ancestor and the executor's `worktree_branch_check` guard
+halts with a base-mismatch fatal — potentially many commits behind, not just one. Run this check
+immediately before capturing `EXPECTED_BASE` so it reflects the most current local state.
+
+```bash
+if [ "$RUNTIME" = "claude" ] && [ "${USE_WORKTREES:-true}" != "false" ]; then
+  _QUICK_SHOULD_DEGRADE=$(gsd_run query worktree.base-check --pick shouldDegrade 2>/dev/null || true)
+  if [ "$_QUICK_SHOULD_DEGRADE" = "true" ]; then
+    _QUICK_DEGRADE_MSG=$(gsd_run query worktree.base-check --pick message 2>/dev/null || true)
+    [ -n "$_QUICK_DEGRADE_MSG" ] && printf '%s\n' "$_QUICK_DEGRADE_MSG" >&2
+    echo "⚠ [#1941] Worktree fork base diverged from orchestrator HEAD — auto-degrading to sequential mode for this quick task to avoid a base-mismatch halt." >&2
+    USE_WORKTREES=false
+  fi
+fi
+```
+
 Capture current HEAD before spawning (used for worktree branch check):
 ```bash
 EXPECTED_BASE=$(git rev-parse HEAD)
diff --git a/src/capability-state.cts b/src/capability-state.cts
index 42fad2b9c..d148d6db7 100644
--- a/src/capability-state.cts
+++ b/src/capability-state.cts
@@ -46,7 +46,7 @@ const { loadConfig } = configLoaderMod;
 
 // eslint-disable-next-line @typescript-eslint/no-require-imports
 import installProfilesMod = require('./install-profiles.cjs');
-const { readActiveProfile, loadSkillsManifest, resolveProfile, parseRequires } = installProfilesMod;
+const { readActiveProfile, loadSkillsManifest, resolveProfile, parseRequires, parseCallsAgents } = installProfilesMod;
 
 // eslint-disable-next-line @typescript-eslint/no-require-imports
 import surfaceMod = require('./surface.cjs');
@@ -384,22 +384,84 @@ function _loadInstalledSkillsManifest(configDir: string): Map<string, string[]>
   return manifest;
 }
 
+/**
+ * #1858 — Build a skill dependency manifest from a FLAT commands/gsd-<stem>.md
+ * source layout (the Claude local project install shape, where the `gsd-`
+ * prefix is baked into each filename at the commands/ level and there is no
+ * commands/gsd/ subdir). Strips the `gsd-` prefix so stems match the nested
+ * loader's output (gsd-validate-phase.md → validate-phase, same as nested
+ * validate-phase.md).
+ *
+ * Map shape is identical to loadSkillsManifest: each stem maps to its
+ * `requires` deps (parsed via the same shared parseRequires) and carries a
+ * companion `_calls_agents_<stem>` key (parsed via parseCallsAgents) so the
+ * flat and nested paths cannot drift.
+ *
+ * Returns an empty Map when the parent directory does not exist or contains
+ * no gsd-*.md files (so _resolveManifest can use size>0 as the "flat layout
+ * present" signal and fall through to the installed-skills branch otherwise).
+ */
+function _loadFlatCommandsGsdManifest(commandsParentDir: string): Map<string, string[]> {
+  const manifest = new Map<string, string[]>();
+  let entries: fs.Dirent[];
+  try {
+    entries = fs.readdirSync(commandsParentDir, { withFileTypes: true });
+  } catch {
+    return manifest;
+  }
+  for (const entry of entries) {
+    if (!entry.isFile()) continue;
+    if (!entry.name.startsWith('gsd-')) continue;
+    if (!entry.name.endsWith('.md')) continue;
+    // Strip 'gsd-' prefix (4 chars) and '.md' suffix (3 chars) → stem.
+    const stem = entry.name.slice(4, -3);
+    if (!stem) continue;
+    // Mirror loadSkillsManifest's try/catch structure exactly: wrap read +
+    // parse + set together so an unreadable file OR a thrown parser degrades
+    // both keys to [] (parity; closes the latent catch-scope drift a reviewer
+    // flagged — both parsers are non-throwing today, but the structural
+    // match future-proofs the "identical Map shape" contract).
+    try {
+      const content = fs.readFileSync(path.join(commandsParentDir, entry.name), 'utf8');
+      manifest.set(stem, parseRequires(content));
+      manifest.set(`_calls_agents_${stem}`, parseCallsAgents(content));
+    } catch {
+      manifest.set(stem, []);
+      manifest.set(`_calls_agents_${stem}`, []);
+    }
+  }
+  return manifest;
+}
+
 /**
  * Resolve the skill dependency manifest for capability-state resolution.
  *
- * Resolution order (fixes #1160 — installed-runtime capability surface):
- *   1. If commandsGsdDir exists, load from source (repo-checkout behavior).
- *   2. Otherwise, fall back to installed skills at configDir/skills/gsd-[stem]/SKILL.md.
+ * Resolution order:
+ *   1. If commandsGsdDir exists, load from the nested source layout
+ *      (repo-checkout behavior: <repo>/commands/gsd/*.md).
+ *   2. #1858 — otherwise, if the flat source layout is present (gsd-<stem>.md
+ *      files in dirname(commandsGsdDir)), load from there. This is the Claude
+ *      local project install shape where commands/gsd/ does not exist but
+ *      commands/gsd-<stem>.md files do.
+ *   3. #1160 — otherwise, fall back to installed skills at
+ *      configDir/skills/gsd-[stem]/SKILL.md.
  *
- * In an installed runtime the commands/gsd source tree is absent; only the
- * skills/ layout exists. Returning an empty manifest caused resolveSurface to
- * materialise the full-sentinel to an empty Set, making every capability appear
- * unsurfaced even when the skill was physically installed.
+ * In an installed runtime both source trees are absent; only the skills/
+ * layout exists. Returning an empty manifest caused resolveSurface to
+ * materialise the full-sentinel to an empty Set, making every skill-bearing
+ * capability appear unsurfaced even when the skill was physically installed
+ * (#1160) or authored as a flat command file (#1858).
  */
 function _resolveManifest(commandsGsdDir: string, configDir: string): Map<string, string[]> {
   if (fs.existsSync(commandsGsdDir)) {
     return loadSkillsManifest(commandsGsdDir);
   }
+  // #1858: flat source layout — gsd-<stem>.md files at dirname(commandsGsdDir).
+  // Only claim the flat branch when it actually has gsd-*.md files; otherwise
+  // fall through to the installed-skills branch (a commands/ dir with no gsd
+  // files must not shadow an installed skills/ tree).
+  const flat = _loadFlatCommandsGsdManifest(path.dirname(commandsGsdDir));
+  if (flat.size > 0) return flat;
   return _loadInstalledSkillsManifest(configDir);
 }
 
@@ -653,6 +715,7 @@ export = {
   // Exported for tests
   _resolveCommandsGsdDir,
   _loadInstalledSkillsManifest,
+  _loadFlatCommandsGsdManifest,
   _resolveManifest,
   _isSafePropKey,
 };
diff --git a/src/install-profiles.cts b/src/install-profiles.cts
index 90674c367..474327ae5 100644
--- a/src/install-profiles.cts
+++ b/src/install-profiles.cts
@@ -875,6 +875,7 @@ export = {
   writeActiveProfile,
   // Shared internals
   parseRequires,
+  parseCallsAgents,
   cleanupStagedSkills,
   // Back-compat / deprecated
   MINIMAL_SKILL_ALLOWLIST,
diff --git a/tests/capability-state.test.cjs b/tests/capability-state.test.cjs
index bd49f73ba..4ab47fecc 100644
--- a/tests/capability-state.test.cjs
+++ b/tests/capability-state.test.cjs
@@ -23,6 +23,7 @@ const {
   isCapabilityActive,
   _isSafePropKey,
   _loadInstalledSkillsManifest,
+  _loadFlatCommandsGsdManifest,
   _resolveManifest,
 } = require('../gsd-core/bin/lib/capability-state.cjs');
 
@@ -824,6 +825,223 @@ describe('cmdCapabilityState — end-to-end via gsd-tools CLI', () => {
 // FAIL before the fix and PASS after, regardless of whether commands/gsd
 // happens to exist in the current checkout.
 
+describe('regressions: flat commands/gsd-<stem>.md layout (#1858)', () => {
+  // Flat command layout (Claude local project install shape): skills live at
+  // <repo>/commands/gsd-<stem>.md — the gsd- prefix is baked into the filename
+  // and there is NO commands/gsd/ subdir. _resolveManifest must detect this
+  // layout, strip the gsd- prefix, and produce the same stems the nested
+  // loader (commands/gsd/<stem>.md) would, or every skill-bearing capability
+  // is silently reported surfaced:false / enabled:false / active:false.
+  function makeFlatCommandMd(stem, requires) {
+    const req = requires ? `requires: [${requires.join(', ')}]` : 'requires: [phase]';
+    return [
+      '---',
+      `name: gsd:${stem}`,
+      `description: ${stem} skill`,
+      'argument-hint: "[phase number]"',
+      'allowed-tools:',
+      '  - Read',
+      req,
+      '---',
+      'Execute end-to-end.',
+    ].join('\n') + '\n';
+  }
+
+  // ── Unit tests for _loadFlatCommandsGsdManifest ─────────────────────────────
+
+  test('_loadFlatCommandsGsdManifest: returns empty map when parent dir absent', () => {
+    const missing = path.join(os.tmpdir(), 'cap-flat-missing-' + Date.now());
+    const manifest = _loadFlatCommandsGsdManifest(missing);
+    assert.ok(manifest instanceof Map, 'should return a Map');
+    assert.strictEqual(manifest.size, 0, 'should be empty when parent dir absent');
+  });
+
+  test('_loadFlatCommandsGsdManifest: scans gsd-<stem>.md and strips the gsd- prefix', () => {
+    const tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'cap-flat-scan-'));
+    try {
+      fs.writeFileSync(path.join(tmpDir, 'gsd-validate-phase.md'), makeFlatCommandMd('validate-phase'), 'utf8');
+      fs.writeFileSync(path.join(tmpDir, 'gsd-secure-phase.md'), makeFlatCommandMd('secure-phase'), 'utf8');
+      // Non-gsd file must be ignored
+      fs.writeFileSync(path.join(tmpDir, 'random-doc.md'), '# not a skill\n', 'utf8');
+      // Non-markdown gsd file must be ignored
+      fs.writeFileSync(path.join(tmpDir, 'gsd-notskill.txt'), 'nope\n', 'utf8');
+
+      const manifest = _loadFlatCommandsGsdManifest(tmpDir);
+      assert.ok(manifest.has('validate-phase'), 'flat gsd-validate-phase.md -> stem validate-phase');
+      assert.ok(manifest.has('secure-phase'), 'flat gsd-secure-phase.md -> stem secure-phase');
+      assert.ok(!manifest.has('gsd-validate-phase'), 'must NOT keep the gsd- prefix on the stem');
+      assert.ok(!manifest.has('random-doc'), 'non-gsd file must be ignored');
+      assert.ok(!manifest.has('notskill'), 'non-.md gsd file must be ignored');
+    } finally {
+      cleanup(tmpDir);
+    }
+  });
+
+  test('_loadFlatCommandsGsdManifest: parses requires via shared parseRequires (no drift)', () => {
+    const tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'cap-flat-req-'));
+    try {
+      fs.writeFileSync(
+        path.join(tmpDir, 'gsd-my-skill.md'),
+        makeFlatCommandMd('my-skill', ['dep-a', 'dep-b']),
+        'utf8',
+      );
+      const manifest = _loadFlatCommandsGsdManifest(tmpDir);
+      assert.deepStrictEqual(manifest.get('my-skill'), ['dep-a', 'dep-b']);
+    } finally {
+      cleanup(tmpDir);
+    }
+  });
+
+  test('_loadFlatCommandsGsdManifest: companion _calls_agents_<stem> key present (parity with nested loader)', () => {
+    const tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'cap-flat-agents-'));
+    try {
+      fs.writeFileSync(path.join(tmpDir, 'gsd-validate-phase.md'), makeFlatCommandMd('validate-phase'), 'utf8');
+      const manifest = _loadFlatCommandsGsdManifest(tmpDir);
+      assert.ok(manifest.has('_calls_agents_validate-phase'),
+        'flat loader must emit the companion _calls_agents_ key (same Map shape as loadSkillsManifest)');
+    } finally {
+      cleanup(tmpDir);
+    }
+  });
+
+  // Low-1 (review): boundary — empty stem (gsd-.md) skipped, single-char stem kept.
+  test('_loadFlatCommandsGsdManifest: skips gsd-.md (empty stem) and keeps single-char stem (slice boundary)', () => {
+    const tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'cap-flat-edge-'));
+    try {
+      fs.writeFileSync(path.join(tmpDir, 'gsd-.md'), makeFlatCommandMd(''), 'utf8');
+      fs.writeFileSync(path.join(tmpDir, 'gsd-x.md'), makeFlatCommandMd('x'), 'utf8');
+      const manifest = _loadFlatCommandsGsdManifest(tmpDir);
+      assert.ok(!manifest.has(''), 'gsd-.md must NOT register an empty-string stem');
+      assert.ok(!manifest.has('_calls_agents_'), 'no companion key for an empty stem');
+      assert.ok(manifest.has('x'), 'gsd-x.md -> single-char stem "x" (slice(4,-3) boundary)');
+    } finally {
+      cleanup(tmpDir);
+    }
+  });
+
+  // Low-2 (review): unreadable file degrades both keys to [] (parity with nested
+  // loader's catch). POSIX-only AND must not run as root — root bypasses POSIX
+  // read permission bits, so chmod 0o000 would NOT make the file unreadable and
+  // the test would assert [] against the real parsed deps (false failure).
+  // Skip on win32 (DEFECT.WINDOWS-POSIX-MODE-BIT-ASSERT) and when getuid()==0.
+  const _skipUnreadable = process.platform === 'win32' || (typeof process.getuid === 'function' && process.getuid() === 0);
+  test('_loadFlatCommandsGsdManifest: unreadable file degrades to empty deps + agents (parity)', { skip: _skipUnreadable }, () => {
+    const tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'cap-flat-unread-'));
+    let madeUnreadable = false;
+    try {
+      const skillPath = path.join(tmpDir, 'gsd-secure.md');
+      fs.writeFileSync(skillPath, '---\nname: gsd:secure\nrequires: [phase]\n---\nbody\n', { mode: 0o644 });
+      fs.chmodSync(skillPath, 0o000);
+      madeUnreadable = true;
+      const manifest = _loadFlatCommandsGsdManifest(tmpDir);
+      assert.deepStrictEqual(manifest.get('secure'), [], 'unreadable file -> empty requires (parity with nested catch)');
+      assert.deepStrictEqual(manifest.get('_calls_agents_secure'), [], 'unreadable file -> empty agents (parity with nested catch)');
+    } finally {
+      // Restore writability so cleanup() can rm the tmp tree.
+      if (madeUnreadable) {
+        try { fs.chmodSync(path.join(tmpDir, 'gsd-secure.md'), 0o644); } catch { /* best effort */ }
+      }
+      cleanup(tmpDir);
+    }
+  });
+
+  // ── _resolveManifest picks the flat branch when nested is absent ────────────
+
+  test('_resolveManifest: detects flat commands/gsd-<stem>.md layout when nested commands/gsd/ is absent (#1858)', () => {
+    const tmpRepo = fs.mkdtempSync(path.join(os.tmpdir(), 'cap-rm-flat-repo-'));
+    try {
+      // Flat source layout: <repo>/commands/gsd-<stem>.md
+      // NO commands/gsd/ subdir, NO skills/ dir.
+      const commandsDir = path.join(tmpRepo, 'commands');
+      fs.mkdirSync(commandsDir, { recursive: true });
+      fs.writeFileSync(path.join(commandsDir, 'gsd-validate-phase.md'), makeFlatCommandMd('validate-phase'), 'utf8');
+      fs.writeFileSync(path.join(commandsDir, 'gsd-secure-phase.md'), makeFlatCommandMd('secure-phase'), 'utf8');
+
+      // commandsGsdDir = <repo>/commands/gsd (nested — does NOT exist).
+      // dirname(commandsGsdDir) = <repo>/commands (where the flat files live).
+      const commandsGsdDir = path.join(commandsDir, 'gsd');
+      // configDir = a separate empty tmp dir (no skills/ → installed fallback empty).
+      const configDir = fs.mkdtempSync(path.join(os.tmpdir(), 'cap-rm-flat-cfg-'));
+      try {
+        const manifest = _resolveManifest(commandsGsdDir, configDir);
+        assert.ok(manifest.has('validate-phase'),
+          'flat layout must populate validate-phase stem (was empty pre-fix → all skill caps unsurfaced)');
+        assert.ok(manifest.has('secure-phase'), 'flat layout must populate secure-phase stem');
+        assert.ok(!manifest.has('gsd-validate-phase'), 'stem must have gsd- prefix stripped');
+      } finally {
+        cleanup(configDir);
+      }
+    } finally {
+      cleanup(tmpRepo);
+    }
+  });
+
+  test('_resolveManifest: flat branch does NOT shadow a populated installed skills dir when no flat files exist', () => {
+    // Precedence: nested > flat-source > installed. If the flat parent dir has
+    // NO gsd-*.md files, the flat loader returns an empty Map and _resolveManifest
+    // must fall through to the installed-skills branch (not return empty).
+    const tmpRepo = fs.mkdtempSync(path.join(os.tmpdir(), 'cap-rm-precedence-'));
+    try {
+      const commandsDir = path.join(tmpRepo, 'commands');
+      fs.mkdirSync(commandsDir, { recursive: true });
+      // No gsd-*.md files in commands/ — flat loader yields empty.
+      // Installed skills present under configDir:
+      const configDir = fs.mkdtempSync(path.join(os.tmpdir(), 'cap-rm-precedence-cfg-'));
+      try {
+        const secureDir = path.join(configDir, 'skills', 'gsd-secure-phase');
+        fs.mkdirSync(secureDir, { recursive: true });
+        fs.writeFileSync(path.join(secureDir, 'SKILL.md'),
+          '---\nname: gsd:secure-phase\nrequires: [phase]\n---\nbody\n', 'utf8');
+
+        const commandsGsdDir = path.join(commandsDir, 'gsd'); // nested absent
+        const manifest = _resolveManifest(commandsGsdDir, configDir);
+        assert.ok(manifest.has('secure-phase'),
+          'when flat dir is empty, installed-skills fallback must still work (precedence flat > installed only when flat non-empty)');
+      } finally {
+        cleanup(configDir);
+      }
+    } finally {
+      cleanup(tmpRepo);
+    }
+  });
+
+  // ── Parity: flat loader produces the same stems as the nested loader ────────
+  // (DEFECT.GENERATIVE-FIX — guards against silent divergence between the two
+  // parallel manifest-builders.)
+
+  test('flat loader and nested loader produce identical stems for the same command set (parity)', () => {
+    const realCommandsGsdDir = path.resolve(__dirname, '..', 'commands', 'gsd');
+    if (!fs.existsSync(realCommandsGsdDir)) return; // skip outside a repo checkout
+    // Build a flat mirror of the real nested commands/gsd/<stem>.md as
+    // commands/gsd-<stem>.md in a temp dir, then compare stem sets.
+    const tmpFlat = fs.mkdtempSync(path.join(os.tmpdir(), 'cap-parity-flat-'));
+    try {
+      const nested = require('../gsd-core/bin/lib/install-profiles.cjs').loadSkillsManifest(realCommandsGsdDir);
+      for (const [stem] of nested) {
+        if (stem.startsWith('_calls_agents_')) continue;
+        const src = path.join(realCommandsGsdDir, stem + '.md');
+        if (!fs.existsSync(src)) continue;
+        fs.writeFileSync(path.join(tmpFlat, 'gsd-' + stem + '.md'), fs.readFileSync(src, 'utf8'), 'utf8');
+      }
+      const flat = _loadFlatCommandsGsdManifest(tmpFlat);
+      const nestedStems = [...nested.keys()].filter((k) => !k.startsWith('_calls_agents_')).sort();
+      const flatStems = [...flat.keys()].filter((k) => !k.startsWith('_calls_agents_')).sort();
+      assert.deepStrictEqual(flatStems, nestedStems,
+        'flat loader stem set must match nested loader stem set for the real command tree');
+      // Nit-2 (review): also compare _calls_agents_<stem> VALUES, not just the
+      // stem set — proves the shared parseCallsAgents output is identical.
+      for (const stem of flatStems) {
+        assert.deepStrictEqual(flat.get(`_calls_agents_${stem}`), nested.get(`_calls_agents_${stem}`),
+          `agent refs for stem "${stem}" must match between flat and nested loaders`);
+        assert.deepStrictEqual(flat.get(stem), nested.get(stem),
+          `requires for stem "${stem}" must match between flat and nested loaders`);
+      }
+    } finally {
+      cleanup(tmpFlat);
+    }
+  });
+});
+
 describe('regressions: installed-runtime capability surface (#1160)', () => {
   // Minimal valid SKILL.md content (frontmatter only — matches what install emits)
   function makeSkillMd(stem) {
diff --git a/tests/fix-1941-quick-worktree-stale-base.test.cjs b/tests/fix-1941-quick-worktree-stale-base.test.cjs
new file mode 100644
index 000000000..0b59589dd
--- /dev/null
+++ b/tests/fix-1941-quick-worktree-stale-base.test.cjs
@@ -0,0 +1,76 @@
+// allow-test-rule: source-text-is-the-product #1941
+// Workflow .md files are the installed AI instructions — their text IS what the runtime
+// loads. Testing text content tests the deployed contract. Per CONTRIBUTING.md exception matrix.
+
+/**
+ * Regression tests for bug #1941: /gsd-quick worktree executor forks from a stale base —
+ * up to many commits behind, not just the one-commit gap #1265 already covers.
+ *
+ * Root cause: Claude Code's isolation="worktree" forks new worktrees from origin/HEAD, not
+ * the live local HEAD. When prior local commits (e.g. earlier quick tasks in the same
+ * session, or this task's own Step 5.6 pre-dispatch plan commit) advance local HEAD without
+ * an intervening `git push`, origin/HEAD stays pinned to a stale ancestor and the executor's
+ * worktree_branch_check guard halts with a base-mismatch fatal. The fix ports the
+ * worktree.base-check auto-degrade pattern already used by execute-phase (#683/#1369) into
+ * quick.md's single-dispatch path.
+ */
+
+const { test, describe } = require('node:test');
+const assert = require('node:assert/strict');
+const fs = require('fs');
+const path = require('path');
+
+const WORKFLOW_PATH = path.join(__dirname, '..', 'gsd-core', 'workflows', 'quick.md');
+
+describe('quick: pre-dispatch worktree base re-check (#1941)', () => {
+  test('workflow file exists', () => {
+    assert.ok(fs.existsSync(WORKFLOW_PATH), 'workflows/quick.md should exist');
+  });
+
+  test('Step 6 runs worktree.base-check before capturing EXPECTED_BASE', () => {
+    const content = fs.readFileSync(WORKFLOW_PATH, 'utf-8');
+    const step6Idx = content.indexOf('**Step 6: Spawn executor**');
+    const baseCheckIdx = content.indexOf('worktree.base-check', step6Idx);
+    const expectedBaseIdx = content.indexOf('EXPECTED_BASE=$(git rev-parse HEAD)', step6Idx);
+    assert.ok(step6Idx !== -1, '"Step 6: Spawn executor" must exist in quick.md');
+    assert.ok(baseCheckIdx !== -1, 'worktree.base-check must be invoked within Step 6');
+    assert.ok(expectedBaseIdx !== -1, 'EXPECTED_BASE capture must exist within Step 6');
+    assert.ok(
+      baseCheckIdx < expectedBaseIdx,
+      'worktree.base-check must run BEFORE EXPECTED_BASE is captured so the degrade decision reflects the most current local HEAD'
+    );
+  });
+
+  test('degrade check references #1941 for traceability', () => {
+    const content = fs.readFileSync(WORKFLOW_PATH, 'utf-8');
+    assert.ok(content.includes('#1941'), 'quick.md must reference #1941');
+  });
+
+  test('degrade check sets USE_WORKTREES=false when shouldDegrade is true', () => {
+    const content = fs.readFileSync(WORKFLOW_PATH, 'utf-8');
+    const baseCheckIdx = content.indexOf('worktree.base-check');
+    const block = content.slice(baseCheckIdx, baseCheckIdx + 600);
+    assert.ok(
+      block.includes('shouldDegrade') && block.includes('USE_WORKTREES=false'),
+      'degrade check must override USE_WORKTREES=false when shouldDegrade is true'
+    );
+  });
+
+  test('degrade check guards on RUNTIME=claude (worktree isolation is Claude Code-specific)', () => {
+    const content = fs.readFileSync(WORKFLOW_PATH, 'utf-8');
+    const baseCheckIdx = content.indexOf('worktree.base-check');
+    const block = content.slice(Math.max(0, baseCheckIdx - 200), baseCheckIdx + 200);
+    assert.ok(
+      block.includes('RUNTIME') && (block.includes('"claude"') || block.includes("'claude'")),
+      'degrade check must guard on RUNTIME=claude'
+    );
+  });
+
+  test('degrade check names origin/HEAD as the stale fork base', () => {
+    const content = fs.readFileSync(WORKFLOW_PATH, 'utf-8');
+    const step6Idx = content.indexOf('**Step 6: Spawn executor**');
+    const nextSection = content.indexOf('\n---', step6Idx);
+    const section = content.slice(step6Idx, nextSection === -1 ? undefined : nextSection);
+    assert.ok(section.includes('origin/HEAD'), 'Step 6 must name origin/HEAD as the stale fork base');
+  });
+});
diff --git a/tests/fixtures/golden-install-parity/antigravity.json b/tests/fixtures/golden-install-parity/antigravity.json
index 828b5aa55..ff545c7c6 100644
--- a/tests/fixtures/golden-install-parity/antigravity.json
+++ b/tests/fixtures/golden-install-parity/antigravity.json
@@ -274,7 +274,7 @@
   "gsd-core/workflows/pr-branch.md": "dc5598ae8accdecd",
   "gsd-core/workflows/profile-user.md": "355af92ac285567f",
   "gsd-core/workflows/progress.md": "79a11ce798082054",
-  "gsd-core/workflows/quick.md": "a6aa362881f4e5da",
+  "gsd-core/workflows/quick.md": "35582887917ef938",
   "gsd-core/workflows/reapply-patches.md": "4dcd6117d0a507ca",
   "gsd-core/workflows/remove-phase.md": "23b9eb0858a2535e",
   "gsd-core/workflows/remove-workspace.md": "d0bd7e0601138798",
diff --git a/tests/fixtures/golden-install-parity/augment.json b/tests/fixtures/golden-install-parity/augment.json
index b11068a30..fb173c13c 100644
--- a/tests/fixtures/golden-install-parity/augment.json
+++ b/tests/fixtures/golden-install-parity/augment.json
@@ -344,7 +344,7 @@
   "gsd-core/workflows/pr-branch.md": "c87db7ac8c28be1b",
   "gsd-core/workflows/profile-user.md": "14263db831230142",
   "gsd-core/workflows/progress.md": "893aa3c36983f74b",
-  "gsd-core/workflows/quick.md": "3bafc0a59cc90d26",
+  "gsd-core/workflows/quick.md": "5790ceb09aa685be",
   "gsd-core/workflows/reapply-patches.md": "39050f72601aec89",
   "gsd-core/workflows/remove-phase.md": "df9a45f0b1880999",
   "gsd-core/workflows/remove-workspace.md": "a7ca66db6b7c132c",
diff --git a/tests/fixtures/golden-install-parity/claude.json b/tests/fixtures/golden-install-parity/claude.json
index 61fab429f..60f0eb61f 100644
--- a/tests/fixtures/golden-install-parity/claude.json
+++ b/tests/fixtures/golden-install-parity/claude.json
@@ -273,7 +273,7 @@
   "gsd-core/workflows/pr-branch.md": "ab157cd8e49621dd",
   "gsd-core/workflows/profile-user.md": "ff3820a27731ceb8",
   "gsd-core/workflows/progress.md": "bd1ecf9207331bda",
-  "gsd-core/workflows/quick.md": "bd56a6313d5ed43c",
+  "gsd-core/workflows/quick.md": "da83b1a15b7f1bf7",
   "gsd-core/workflows/reapply-patches.md": "ba9406b60f2c4041",
   "gsd-core/workflows/remove-phase.md": "ada8a0546c686483",
   "gsd-core/workflows/remove-workspace.md": "f3ab3a88a7e9e1ed",
diff --git a/tests/fixtures/golden-install-parity/cline.json b/tests/fixtures/golden-install-parity/cline.json
index 57b75c397..4bc06f184 100644
--- a/tests/fixtures/golden-install-parity/cline.json
+++ b/tests/fixtures/golden-install-parity/cline.json
@@ -277,7 +277,7 @@
   "gsd-core/workflows/pr-branch.md": "9923878a4f6a2d91",
   "gsd-core/workflows/profile-user.md": "26f74db0a7fcd268",
   "gsd-core/workflows/progress.md": "9f326d63afb4b76b",
-  "gsd-core/workflows/quick.md": "10051a9b41d5d210",
+  "gsd-core/workflows/quick.md": "68a9dfcd53f0859f",
   "gsd-core/workflows/reapply-patches.md": "eb4272145a117904",
   "gsd-core/workflows/remove-phase.md": "e336350f8113a328",
   "gsd-core/workflows/remove-workspace.md": "e685dfbd736dfd90",
diff --git a/tests/fixtures/golden-install-parity/codebuddy.json b/tests/fixtures/golden-install-parity/codebuddy.json
index ff6963ad3..578f0fb21 100644
--- a/tests/fixtures/golden-install-parity/codebuddy.json
+++ b/tests/fixtures/golden-install-parity/codebuddy.json
@@ -344,7 +344,7 @@
   "gsd-core/workflows/pr-branch.md": "c87db7ac8c28be1b",
   "gsd-core/workflows/profile-user.md": "4fa910d15dea5695",
   "gsd-core/workflows/progress.md": "893aa3c36983f74b",
-  "gsd-core/workflows/quick.md": "5e7dcdd864513b87",
+  "gsd-core/workflows/quick.md": "9033dbe58443af36",
   "gsd-core/workflows/reapply-patches.md": "39050f72601aec89",
   "gsd-core/workflows/remove-phase.md": "df9a45f0b1880999",
   "gsd-core/workflows/remove-workspace.md": "a7ca66db6b7c132c",
diff --git a/tests/fixtures/golden-install-parity/codex.json b/tests/fixtures/golden-install-parity/codex.json
index 7e334a502..994283b9b 100644
--- a/tests/fixtures/golden-install-parity/codex.json
+++ b/tests/fixtures/golden-install-parity/codex.json
@@ -309,7 +309,7 @@
   "gsd-core/workflows/pr-branch.md": "d13e1cc81de40896",
   "gsd-core/workflows/profile-user.md": "05828c8cc61ef384",
   "gsd-core/workflows/progress.md": "7bedc431bb55edb8",
-  "gsd-core/workflows/quick.md": "85fb48e52f0b3725",
+  "gsd-core/workflows/quick.md": "3e7686705da2af19",
   "gsd-core/workflows/reapply-patches.md": "26297b84736e66a4",
   "gsd-core/workflows/remove-phase.md": "9ee0fddd11a0d9d4",
   "gsd-core/workflows/remove-workspace.md": "19d7465aaa50cb62",
diff --git a/tests/fixtures/golden-install-parity/copilot.json b/tests/fixtures/golden-install-parity/copilot.json
index 608acbaad..dc09143bc 100644
--- a/tests/fixtures/golden-install-parity/copilot.json
+++ b/tests/fixtures/golden-install-parity/copilot.json
@@ -275,7 +275,7 @@
   "gsd-core/workflows/pr-branch.md": "2833905f119b5722",
   "gsd-core/workflows/profile-user.md": "5cc032206c99ef71",
   "gsd-core/workflows/progress.md": "6b9a84a43dc55af5",
-  "gsd-core/workflows/quick.md": "89c34e07f1bf6f53",
+  "gsd-core/workflows/quick.md": "7ddfe17f048541ec",
   "gsd-core/workflows/reapply-patches.md": "8fd59e24b486f180",
   "gsd-core/workflows/remove-phase.md": "e262654e319d1bc4",
   "gsd-core/workflows/remove-workspace.md": "ceddfeef5f2d6754",
diff --git a/tests/fixtures/golden-install-parity/cursor.json b/tests/fixtures/golden-install-parity/cursor.json
index 01081c29a..b71bb0b86 100644
--- a/tests/fixtures/golden-install-parity/cursor.json
+++ b/tests/fixtures/golden-install-parity/cursor.json
@@ -344,7 +344,7 @@
   "gsd-core/workflows/pr-branch.md": "c67d90c65da47168",
   "gsd-core/workflows/profile-user.md": "8c943983241260b5",
   "gsd-core/workflows/progress.md": "65aabee5e8a6dd82",
-  "gsd-core/workflows/quick.md": "db98fdbe79d68ffc",
+  "gsd-core/workflows/quick.md": "762256cf6d177c06",
   "gsd-core/workflows/reapply-patches.md": "ba9406b60f2c4041",
   "gsd-core/workflows/remove-phase.md": "ada8a0546c686483",
   "gsd-core/workflows/remove-workspace.md": "433affcd1a200826",
diff --git a/tests/fixtures/golden-install-parity/hermes.json b/tests/fixtures/golden-install-parity/hermes.json
index 6101532d4..f7f49191e 100644
--- a/tests/fixtures/golden-install-parity/hermes.json
+++ b/tests/fixtures/golden-install-parity/hermes.json
@@ -274,7 +274,7 @@
   "gsd-core/workflows/pr-branch.md": "ecabd55e4eabf229",
   "gsd-core/workflows/profile-user.md": "de5030437226cf2c",
   "gsd-core/workflows/progress.md": "f18db000584d9cb1",
-  "gsd-core/workflows/quick.md": "66b26d6fe2bd4d71",
+  "gsd-core/workflows/quick.md": "5044ce4e7512e174",
   "gsd-core/workflows/reapply-patches.md": "158083a310859594",
   "gsd-core/workflows/remove-phase.md": "fce799aae3ab2715",
   "gsd-core/workflows/remove-workspace.md": "8facde381657dd71",
diff --git a/tests/fixtures/golden-install-parity/kilo.json b/tests/fixtures/golden-install-parity/kilo.json
index 5d890290e..f6cef1739 100644
--- a/tests/fixtures/golden-install-parity/kilo.json
+++ b/tests/fixtures/golden-install-parity/kilo.json
@@ -344,7 +344,7 @@
   "gsd-core/workflows/pr-branch.md": "ab157cd8e49621dd",
   "gsd-core/workflows/profile-user.md": "203ebe3f8f3876a8",
   "gsd-core/workflows/progress.md": "9381c59676ccb937",
-  "gsd-core/workflows/quick.md": "11ba83f6350462fb",
+  "gsd-core/workflows/quick.md": "fd7461e5a92fe450",
   "gsd-core/workflows/reapply-patches.md": "becf9728cdb124c4",
   "gsd-core/workflows/remove-phase.md": "ada8a0546c686483",
   "gsd-core/workflows/remove-workspace.md": "fc83f362a2d0a1b7",
diff --git a/tests/fixtures/golden-install-parity/kimi.json b/tests/fixtures/golden-install-parity/kimi.json
index 38a6bf88a..61ef75522 100644
--- a/tests/fixtures/golden-install-parity/kimi.json
+++ b/tests/fixtures/golden-install-parity/kimi.json
@@ -310,7 +310,7 @@
   "gsd-core/workflows/pr-branch.md": "c87db7ac8c28be1b",
   "gsd-core/workflows/profile-user.md": "5abfae83739fa978",
   "gsd-core/workflows/progress.md": "893aa3c36983f74b",
-  "gsd-core/workflows/quick.md": "d722803b72217377",
+  "gsd-core/workflows/quick.md": "e265e01cfe117215",
   "gsd-core/workflows/reapply-patches.md": "39050f72601aec89",
   "gsd-core/workflows/remove-phase.md": "df9a45f0b1880999",
   "gsd-core/workflows/remove-workspace.md": "a7ca66db6b7c132c",
diff --git a/tests/fixtures/golden-install-parity/opencode.json b/tests/fixtures/golden-install-parity/opencode.json
index 2cd9274fd..7da30507c 100644
--- a/tests/fixtures/golden-install-parity/opencode.json
+++ b/tests/fixtures/golden-install-parity/opencode.json
@@ -344,7 +344,7 @@
   "gsd-core/workflows/pr-branch.md": "929b7cb0c99c7b9e",
   "gsd-core/workflows/profile-user.md": "248d59a31948e0ed",
   "gsd-core/workflows/progress.md": "8fc3404087f50b95",
-  "gsd-core/workflows/quick.md": "3866a5259e8912d8",
+  "gsd-core/workflows/quick.md": "10cc8ddd4bc3f0ee",
   "gsd-core/workflows/reapply-patches.md": "a0e9b53f90abceb2",
   "gsd-core/workflows/remove-phase.md": "dea4661e8f89596f",
   "gsd-core/workflows/remove-workspace.md": "446847e71aa52504",
diff --git a/tests/fixtures/golden-install-parity/qwen.json b/tests/fixtures/golden-install-parity/qwen.json
index 7d69d0606..a75c2e6db 100644
--- a/tests/fixtures/golden-install-parity/qwen.json
+++ b/tests/fixtures/golden-install-parity/qwen.json
@@ -274,7 +274,7 @@
   "gsd-core/workflows/pr-branch.md": "cef0f65b16d500b4",
   "gsd-core/workflows/profile-user.md": "263c0693563d98da",
   "gsd-core/workflows/progress.md": "3b1b2142a74af85c",
-  "gsd-core/workflows/quick.md": "518740e30dcd4da3",
+  "gsd-core/workflows/quick.md": "0a9a7dacc73f8e53",
   "gsd-core/workflows/reapply-patches.md": "de0ee8acfe7245b2",
   "gsd-core/workflows/remove-phase.md": "e8ae4fbbfac700f0",
   "gsd-core/workflows/remove-workspace.md": "4ac64de862dc650e",
diff --git a/tests/fixtures/golden-install-parity/trae.json b/tests/fixtures/golden-install-parity/trae.json
index fffc076bb..b1f651209 100644
--- a/tests/fixtures/golden-install-parity/trae.json
+++ b/tests/fixtures/golden-install-parity/trae.json
@@ -274,7 +274,7 @@
   "gsd-core/workflows/pr-branch.md": "79fd55b88ea2db9c",
   "gsd-core/workflows/profile-user.md": "672821e6b1266645",
   "gsd-core/workflows/progress.md": "94768f835b0b8908",
-  "gsd-core/workflows/quick.md": "8ac5f3919f754499",
+  "gsd-core/workflows/quick.md": "9bbf907e39688638",
   "gsd-core/workflows/reapply-patches.md": "21b38c374f19fd78",
   "gsd-core/workflows/remove-phase.md": "a46c2fe853bf4e86",
   "gsd-core/workflows/remove-workspace.md": "ae0e1c6d4438d663",
diff --git a/tests/fixtures/golden-install-parity/windsurf.json b/tests/fixtures/golden-install-parity/windsurf.json
index 93396735f..08164b70d 100644
--- a/tests/fixtures/golden-install-parity/windsurf.json
+++ b/tests/fixtures/golden-install-parity/windsurf.json
@@ -274,7 +274,7 @@
   "gsd-core/workflows/pr-branch.md": "acd59f915d018ad4",
   "gsd-core/workflows/profile-user.md": "c4313672b81b5bcd",
   "gsd-core/workflows/progress.md": "18813a345bd2343a",
-  "gsd-core/workflows/quick.md": "0fcad72e7dbe99c9",
+  "gsd-core/workflows/quick.md": "3acd391cc0c3813a",
   "gsd-core/workflows/reapply-patches.md": "d449a23d3acf6379",
   "gsd-core/workflows/remove-phase.md": "e7a6af429b36e77b",
   "gsd-core/workflows/remove-workspace.md": "b5e60fbb33b3e33a",
diff --git a/tests/fixtures/golden-install-parity/zcode.json b/tests/fixtures/golden-install-parity/zcode.json
index d506e7cd6..c46db6812 100644
--- a/tests/fixtures/golden-install-parity/zcode.json
+++ b/tests/fixtures/golden-install-parity/zcode.json
@@ -344,7 +344,7 @@
   "gsd-core/workflows/pr-branch.md": "c87db7ac8c28be1b",
   "gsd-core/workflows/profile-user.md": "e23bea0a69c0bb4b",
   "gsd-core/workflows/progress.md": "893aa3c36983f74b",
-  "gsd-core/workflows/quick.md": "1bc59c4d97fed876",
+  "gsd-core/workflows/quick.md": "5747c2d8a37affbb",
   "gsd-core/workflows/reapply-patches.md": "39050f72601aec89",
   "gsd-core/workflows/remove-phase.md": "df9a45f0b1880999",
   "gsd-core/workflows/remove-workspace.md": "a7ca66db6b7c132c",
diff --git a/tests/workflow-size-baseline.json b/tests/workflow-size-baseline.json
index c5f07afdb..29fcbfed7 100644
--- a/tests/workflow-size-baseline.json
+++ b/tests/workflow-size-baseline.json
@@ -58,7 +58,7 @@
   "pr-branch.md": 15963,
   "profile-user.md": 21246,
   "progress.md": 30599,
-  "quick.md": 49183,
+  "quick.md": 50452,
   "reapply-patches.md": 20312,
   "remove-phase.md": 8513,
   "remove-workspace.md": 7551,