diff --git a/eslint-rules/no-adhoc-timeout-literal.allowlist.json b/eslint-rules/no-adhoc-timeout-literal.allowlist.json
index 0733f60d2..47efb5bee 100644
--- a/eslint-rules/no-adhoc-timeout-literal.allowlist.json
+++ b/eslint-rules/no-adhoc-timeout-literal.allowlist.json
@@ -1,10 +1,7 @@
 [
   "tests/adr-612-bracket-coherence.test.cjs",
   "tests/adr-612-bracket-read-tolerance.test.cjs",
-  "tests/adr-index-gate.test.cjs",
   "tests/adr857-core-without-capabilities.test.cjs",
-  "tests/api-coverage-gate-e2e.test.cjs",
-  "tests/api-coverage.test.cjs",
   "tests/assumption-delta-checkpoint-e2e.test.cjs",
   "tests/assumption-delta.test.cjs",
   "tests/capability-cli.test.cjs",
@@ -13,9 +10,7 @@
   "tests/capability-trust.test.cjs",
   "tests/capability-validator-task-content-resolver.test.cjs",
   "tests/capability-writer.test.cjs",
-  "tests/changeset-new.test.cjs",
   "tests/check-env.test.cjs",
-  "tests/check-glossary-refs.test.cjs",
   "tests/check-predicate.test.cjs",
   "tests/cjs-command-router-adapter.test.cjs",
   "tests/code-review-pipeline-regression.test.cjs",
@@ -24,24 +19,16 @@
   "tests/config-get-default.test.cjs",
   "tests/dispatcher.test.cjs",
   "tests/effort-surface-axis.test.cjs",
-  "tests/emitted-ack-trailer.test.cjs",
-  "tests/emitted-attribution.test.cjs",
   "tests/federated-config.test.cjs",
   "tests/gate-predicate-evaluator.test.cjs",
-  "tests/gen-context-index.test.cjs",
-  "tests/gen-health-docs.test.cjs",
-  "tests/gen-section-manifest.test.cjs",
-  "tests/gen-state-md-docs.test.cjs",
   "tests/graphify.test.cjs",
   "tests/gsd-check-update-worker-platform-gate.test.cjs",
   "tests/gsd-mcp-server-bin.test.cjs",
   "tests/gsd-statusline.test.cjs",
   "tests/health-validation.test.cjs",
   "tests/init.test.cjs",
-  "tests/lint-docs-command-form.test.cjs",
   "tests/locking-bugs-1909-1916-1925-1927.test.cjs",
   "tests/milestone-lock.test.cjs",
-  "tests/no-pending-3212-markers.test.cjs",
   "tests/pattern.test.cjs",
   "tests/perf-316-state-lock-buffer-alloc.test.cjs",
   "tests/perf-317-context-monitor-fs.test.cjs",
@@ -53,7 +40,6 @@
   "tests/policy-160-route0-resume.test.cjs",
   "tests/prohibition-enforcement.test.cjs",
   "tests/quick-batch.test.cjs",
-  "tests/representative-corpus.test.cjs",
   "tests/review-lane-invocation.test.cjs",
   "tests/reviewer-manifest-body.test.cjs",
   "tests/reviewer-trust-disclosure.test.cjs",
diff --git a/tests/adr-index-gate.test.cjs b/tests/adr-index-gate.test.cjs
index 9a7a2caf7..6a80268ed 100644
--- a/tests/adr-index-gate.test.cjs
+++ b/tests/adr-index-gate.test.cjs
@@ -18,6 +18,7 @@ const { spawnSync } = require('node:child_process');
 const { createTempDir, cleanup } = require('./helpers.cjs');
 const { copyScriptWithDeps } = require('./helpers/copy-script-fixture.cjs');
 const { findTableWithColumns } = require('../gsd-core/bin/lib/markdown-table.cjs');
+const { GENERATOR_SCRIPT_TIMEOUT_MS } = require('./helpers/timeouts.cjs');
 
 const REPO_ROOT = path.resolve(__dirname, '..');
 const SCRIPT_REL = path.join('scripts', 'gen-adr-index.cjs');
@@ -61,7 +62,7 @@ function run(root, args = []) {
   const res = spawnSync(process.execPath, [path.join(root, SCRIPT_REL), ...args], {
     cwd: root,
     encoding: 'utf8',
-    timeout: 30_000,
+    timeout: GENERATOR_SCRIPT_TIMEOUT_MS,
   });
   if (res.error) throw res.error;
   return { status: res.status, stdout: res.stdout || '', stderr: res.stderr || '' };
diff --git a/tests/api-coverage-gate-e2e.test.cjs b/tests/api-coverage-gate-e2e.test.cjs
index 809912728..f9061bce4 100644
--- a/tests/api-coverage-gate-e2e.test.cjs
+++ b/tests/api-coverage-gate-e2e.test.cjs
@@ -23,6 +23,7 @@ const path = require('node:path');
 
 const { cleanup, TEST_ENV_BASE } = require('./helpers.cjs');
 const { runNode, OUTCOME } = require('./helpers/process-seam.cjs');
+const { LOOP_HOOK_POINT_CLI_TIMEOUT_MS } = require('./helpers/timeouts.cjs');
 // In-process seam for the fail-closed read-injection tests at the bottom of this
 // file (#2365 review): readPhaseScope is the pure phase-scope reader behind the
 // gate. Those tests monkeypatch fs rather than drive a subprocess.
@@ -39,7 +40,7 @@ function runTools(args, cwd) {
   const r = runNode([TOOLS_PATH, ...argv], {
     cwd,
     env: { ...process.env, ...TEST_ENV_BASE },
-    timeoutMs: 60000,
+    timeoutMs: LOOP_HOOK_POINT_CLI_TIMEOUT_MS,
   });
   if (r.outcome === OUTCOME.EXITED && r.exitCode === 0) {
     return { success: true, output: r.stdout.trim(), exitCode: 0, error: '' };
diff --git a/tests/api-coverage.test.cjs b/tests/api-coverage.test.cjs
index bbc9058ba..67bf049d6 100644
--- a/tests/api-coverage.test.cjs
+++ b/tests/api-coverage.test.cjs
@@ -17,6 +17,7 @@ const assert = require('node:assert/strict');
 const { spawnSync } = require('node:child_process');
 const path = require('node:path');
 const fc = require('fast-check');
+const { PROBE_TIMEOUT_MS } = require('./helpers/timeouts.cjs');
 
 const MODULE_PATH = path.join(__dirname, '..', 'gsd-core', 'bin', 'lib', 'api-coverage.cjs');
 
@@ -985,7 +986,7 @@ describe('api-coverage CLI — STDIN + exit codes', () => {
     const r = spawnSync(process.execPath, [CLI, '--json'], {
       input: stdin,
       encoding: 'utf-8',
-      timeout: 15000,
+      timeout: PROBE_TIMEOUT_MS,
     });
     return { exitCode: r.status, stdout: r.stdout, stderr: r.stderr };
   }
@@ -1016,7 +1017,6 @@ describe('api-coverage CLI — NO_INPUT / UNAVAILABLE (ADR-3889 Phase 3, #3907)'
   const INJECT_STDIN_ERROR = path.join(__dirname, 'helpers', 'inject-stdin-error.cjs');
   const { exitCodeFor } = require('../gsd-core/bin/lib/exit-code-registry.cjs');
   const { runNode } = require('./helpers/process-seam.cjs');
-  const { PROBE_TIMEOUT_MS } = require('./helpers/timeouts.cjs');
 
   function runCliJson(stdin, extraArgs = [], extraEnv = {}) {
     const r = runNode([CLI, '--json', ...extraArgs], {
diff --git a/tests/changeset-new.test.cjs b/tests/changeset-new.test.cjs
index 2d72d3f13..be7e7c659 100644
--- a/tests/changeset-new.test.cjs
+++ b/tests/changeset-new.test.cjs
@@ -16,6 +16,7 @@ const { generateFragmentName, scaffoldFragment, parseFragment, parseArgs } = (()
 })();
 const { FRAGMENT_ERROR } = require(path.join(ROOT, 'scripts', 'changeset', 'parse.cjs'));
 const { cleanup } = require('./helpers.cjs');
+const { QUICK_SPAWN_TIMEOUT_MS } = require('./helpers/timeouts.cjs');
 
 const NEW_CJS = path.join(ROOT, 'scripts', 'changeset', 'new.cjs');
 
@@ -114,7 +115,7 @@ describe('changeset new: --pr 0 placeholder acceptance (bug #1224)', () => {
       const result = spawnSync(
         process.execPath,
         [NEW_CJS, '--type', 'Fixed', '--pr', '0', '--body', 'placeholder for pr-zero.', '--repo', isolatedDir],
-        { encoding: 'utf8', timeout: 10000 },
+        { encoding: 'utf8', timeout: QUICK_SPAWN_TIMEOUT_MS },
       );
 
       // The bug: old main() did `if (!opts.pr)` → exit 2. Fixed: exit 0.
diff --git a/tests/check-glossary-refs.test.cjs b/tests/check-glossary-refs.test.cjs
index fdf586419..e2a0aeb82 100644
--- a/tests/check-glossary-refs.test.cjs
+++ b/tests/check-glossary-refs.test.cjs
@@ -17,6 +17,7 @@ const { spawnSync } = require('node:child_process');
 
 const { createTempDir, cleanup } = require('./helpers.cjs');
 const { copyScriptWithDeps } = require('./helpers/copy-script-fixture.cjs');
+const { GENERATOR_SCRIPT_TIMEOUT_MS } = require('./helpers/timeouts.cjs');
 
 const REPO_ROOT = path.resolve(__dirname, '..');
 const SCRIPT_REL = path.join('scripts', 'check-glossary-refs.cjs');
@@ -67,7 +68,7 @@ function run(root, args = []) {
   const res = spawnSync(process.execPath, [path.join(root, SCRIPT_REL), ...args], {
     cwd: root,
     encoding: 'utf8',
-    timeout: 30_000,
+    timeout: GENERATOR_SCRIPT_TIMEOUT_MS,
   });
   if (res.error) throw res.error;
   return { status: res.status, stdout: res.stdout || '', stderr: res.stderr || '' };
@@ -227,7 +228,7 @@ test('the real script runs cleanly against the real repo without crashing', () =
   const res = spawnSync(process.execPath, [path.join(REPO_ROOT, SCRIPT_REL), '--check'], {
     cwd: REPO_ROOT,
     encoding: 'utf8',
-    timeout: 30_000,
+    timeout: GENERATOR_SCRIPT_TIMEOUT_MS,
   });
   assert.equal(res.error, undefined, `spawn must not error: ${res.error}`);
   assert.ok(res.status === 0 || res.status === 1, `expected exit 0 or 1, got ${res.status} (stderr: ${res.stderr})`);
diff --git a/tests/emitted-ack-trailer.test.cjs b/tests/emitted-ack-trailer.test.cjs
index 039bd5f16..d58774156 100644
--- a/tests/emitted-ack-trailer.test.cjs
+++ b/tests/emitted-ack-trailer.test.cjs
@@ -794,6 +794,17 @@ describe('hostile IO: uncomputable range, subprocess failure, timeout', () => {
     );
   });
 
+  /**
+   * Deliberately, impossibly tiny -- NOT a generous-headroom bound like every
+   * other timeout constant in this test suite. Used to FORCE a TIMED_OUT
+   * outcome against an artificially huge git history (see
+   * growHistoryFastImport above), proving "an unreadable-in-time git call
+   * must throw a timeout, never hang." Named and commented distinctly so a
+   * future reader never mistakes this for a real operation-duration budget
+   * and "fixes" it by raising it.
+   */
+  const IMPOSSIBLY_SHORT_GIT_TIMEOUT_MS = 20;
+
   test('git log is bounded by a timeout — row 24', (t) => {
     const dir = makeTempRepo('gsd-ack-trailer-24-');
     withCleanup(t, dir);
@@ -801,7 +812,9 @@ describe('hostile IO: uncomputable range, subprocess failure, timeout', () => {
 
     const start = Date.now();
     assert.throws(
-      () => readAckTrailers({ baseRef: rootSha, headRef: 'HEAD', cwd: dir, timeoutMs: 20 }),
+      () => readAckTrailers({
+        baseRef: rootSha, headRef: 'HEAD', cwd: dir, timeoutMs: IMPOSSIBLY_SHORT_GIT_TIMEOUT_MS,
+      }),
       /time/i,
       'an unreadable-in-time git call must throw a timeout, never hang',
     );
diff --git a/tests/emitted-attribution.test.cjs b/tests/emitted-attribution.test.cjs
index 494438e05..dade76387 100644
--- a/tests/emitted-attribution.test.cjs
+++ b/tests/emitted-attribution.test.cjs
@@ -90,6 +90,56 @@ const {
   resolveBaseline,
 } = require('./helpers/emitted-baseline.cjs');
 
+/**
+ * git plumbing via a scratch index against this repo's REAL object
+ * database (never a throwaway fixture) -- run through this file's own
+ * hand-rolled git-spawn helper (never the shared
+ * tests/helpers/git-fixture.cjs). Shares the REAL_REPO_GIT_TIMEOUT_MS class
+ * with tests/no-pending-3212-markers.test.cjs's `git ls-files` call --
+ * promoted to tests/helpers/timeouts.cjs rather than kept file-local once a
+ * second file was found sharing the exact same value and shape.
+ */
+const { REAL_REPO_GIT_TIMEOUT_MS } = require('./helpers/timeouts.cjs');
+
+/**
+ * git fixture CONSTRUCTION (init/config/add/commit) against a genuinely
+ * fresh temp repo, via this file's own hand-rolled git-spawn helper --
+ * correction from an earlier pass that conflated this with
+ * REAL_REPO_GIT_TIMEOUT_MS's real-repo-tree class; a Standards-axis review
+ * caught that this site's `repo` is a throwaway mkdtemp fixture
+ * (createTempDir + git init), not the real repo tree. Distinct from the
+ * SHARED tests/helpers/git-fixture.cjs's own GIT_FIXTURE_TIMEOUT_MS
+ * (60000ms, a six-spawn construction sequence): this site rolls its own,
+ * lighter five-spawn sequence at a genuinely different pre-existing bound,
+ * so reusing that shared constant would silently double this site's
+ * budget. No fresh bench data justifies a different number, so the
+ * pre-existing 30000ms literal is preserved exactly under this name.
+ */
+const FRESH_FIXTURE_GIT_TIMEOUT_MS = 30_000;
+
+/**
+ * node:test's own per-test timeout option (NOT a subprocess spawn bound) --
+ * bounds the whole test body for this file's two heaviest tests: a real
+ * worktree checkout, `npm run build:lib`, a full multi-runtime install
+ * pass, and real git resolution. A completely different mechanism from
+ * every spawnSync/execFileSync timeout in this file or in
+ * tests/helpers/timeouts.cjs. No fresh bench data justifies a different
+ * number, so the pre-existing 480000ms literal is preserved exactly.
+ */
+const HEAVY_REAL_TREE_TEST_TIMEOUT_MS = 480_000;
+
+/**
+ * Runs the exact same script as the shared BUILD_TIMEOUT_MS constant
+ * (scripts/build-hooks.js) but at 4x that constant's bound. This site
+ * sits inside "differential attribution over the real tree", the single
+ * heaviest test in the suite, where elevated system load plausibly
+ * justifies the wider margin -- not equalized to the lighter shared norm
+ * without bench data. Coincides numerically with INSTALL_TIMEOUT_MS (a
+ * full installer run, an unrelated operation) -- kept separate. No fresh
+ * bench data justifies a different number, so the pre-existing 120000ms
+ * literal is preserved exactly.
+ */
+const BUILD_HOOKS_UNDER_LOAD_TIMEOUT_MS = 120_000;
 
 const SHA_A = 'a'.repeat(40);
 const SHA_B = 'b'.repeat(40);
@@ -1425,7 +1475,7 @@ test('an unreadable baseline surfaces an error', () => {
 test(
   'buildBaselineAtRef resolves a baseline via the in-job build even when the generator '
   + 'script is absent at the ref (#2767 regression)',
-  { timeout: 480_000 },
+  { timeout: HEAVY_REAL_TREE_TEST_TIMEOUT_MS },
   (t) => {
     // Mirrors "differential attribution over the real tree": install output is
     // platform-specific on Windows, and this drives the same heavy worktree +
@@ -1476,7 +1526,7 @@ test(
     // closed. Reusing the SAME helper `buildBaselineAtRef` now uses (below) rather than
     // hand-rolling the flag here keeps the fix from silently diverging per call site.
     const run = (...args) => execFileSync('git', [...safeDirArgs(REPO_ROOT), ...args], {
-      cwd: REPO_ROOT, encoding: 'utf8', timeout: 30_000, env: gitEnv, stdio: ['ignore', 'pipe', 'pipe'],
+      cwd: REPO_ROOT, encoding: 'utf8', timeout: REAL_REPO_GIT_TIMEOUT_MS, env: gitEnv, stdio: ['ignore', 'pipe', 'pipe'],
     }).trim();
 
     const headSha = run('rev-parse', 'HEAD');
@@ -1492,7 +1542,7 @@ test(
     // otherwise this test would prove nothing.
     assert.throws(
       () => execFileSync('git', [...safeDirArgs(REPO_ROOT), 'cat-file', '-e', `${syntheticSha}:scripts/gen-emitted-baseline.cjs`], {
-        cwd: REPO_ROOT, encoding: 'utf8', timeout: 30_000, stdio: 'pipe',
+        cwd: REPO_ROOT, encoding: 'utf8', timeout: REAL_REPO_GIT_TIMEOUT_MS, stdio: 'pipe',
       }),
       /./,
       'the synthetic ref must genuinely lack the generator script for this test to prove anything',
@@ -1936,7 +1986,7 @@ test('baseline families are enumerated from the ref, not from the current regist
   // this same process just created with `mkdtempSync` + `git init`, so its owner is
   // always the uid running the test regardless of container — it is never the
   // externally-mounted repo path the dubious-ownership check reacts to.
-  const run = (...args) => execFileSync('git', args, { cwd: repo, encoding: 'utf8', timeout: 30_000 });
+  const run = (...args) => execFileSync('git', args, { cwd: repo, encoding: 'utf8', timeout: FRESH_FIXTURE_GIT_TIMEOUT_MS });
 
   run('init', '--quiet', '-b', 'main');
   run('config', 'user.email', 'test@example.invalid');
@@ -2050,7 +2100,7 @@ test('property: reported added/dropped are exactly the set differences', () => {
 // the working-tree fixtures, which would be whatever this PR's author regenerated;
 // comparing against those would be vacuous.
 
-test('differential attribution over the real tree', { timeout: 480_000 }, async (t) => {
+test('differential attribution over the real tree', { timeout: HEAVY_REAL_TREE_TEST_TIMEOUT_MS }, async (t) => {
   if (process.platform === 'win32') {
     // Mirrors the golden harness: install output is platform-specific on Windows
     // (backslash paths), so parity is asserted on macOS + Linux. An explicit t.skip,
@@ -2062,7 +2112,7 @@ test('differential attribution over the real tree', { timeout: 480_000 }, async
   // hooks/dist is gitignored and built (DEFECT.HOOKS-DIST-SCOPED-CI): the scoped CI
   // lane does not run build:hooks, so a real install there would emit no hooks/ dir.
   // Build idempotently, exactly as the golden harness does.
-  execFileSync(process.execPath, [BUILD_SCRIPT], { encoding: 'utf-8', stdio: 'pipe', timeout: 120_000 });
+  execFileSync(process.execPath, [BUILD_SCRIPT], { encoding: 'utf-8', stdio: 'pipe', timeout: BUILD_HOOKS_UNDER_LOAD_TIMEOUT_MS });
 
   // The base ref is not universally available. The gsd-test runner shallow-clones and
   // merges base+head, so no `origin/*` remote-tracking ref exists in the container —
diff --git a/tests/gen-context-index.test.cjs b/tests/gen-context-index.test.cjs
index cbd856620..b8001fc51 100644
--- a/tests/gen-context-index.test.cjs
+++ b/tests/gen-context-index.test.cjs
@@ -44,6 +44,7 @@ const { execFileSync } = require('node:child_process');
 
 const { createTempDir, cleanup } = require('./helpers.cjs');
 const { serializeIndex, buildFreshIndex, checkReport, REASON } = require('../scripts/gen-context-index.cjs');
+const { GENERATOR_SCRIPT_TIMEOUT_MS } = require('./helpers/timeouts.cjs');
 
 const ROOT = path.resolve(__dirname, '..');
 const SCRIPT = path.join(ROOT, 'scripts', 'gen-context-index.cjs');
@@ -71,7 +72,7 @@ function runGenContextIndex(args, paths = {}) {
       cwd: ROOT,
       encoding: 'utf8',
       stdio: ['pipe', 'pipe', 'pipe'],
-      timeout: 30000,
+      timeout: GENERATOR_SCRIPT_TIMEOUT_MS,
     });
     return { code: 0, stdout, stderr: '' };
   } catch (err) {
diff --git a/tests/gen-health-docs.test.cjs b/tests/gen-health-docs.test.cjs
index 24b6c474f..21e095c1a 100644
--- a/tests/gen-health-docs.test.cjs
+++ b/tests/gen-health-docs.test.cjs
@@ -18,6 +18,7 @@ const path = require('node:path');
 const { execFileSync } = require('node:child_process');
 
 const { createTempDir, cleanup } = require('./helpers.cjs');
+const { GENERATOR_SCRIPT_TIMEOUT_MS } = require('./helpers/timeouts.cjs');
 const {
   buildErrorCodeRows,
   renderErrorCodesRegion,
@@ -54,7 +55,7 @@ function runGenHealthDocs(args, cwd = ROOT) {
       cwd,
       encoding: 'utf8',
       stdio: ['pipe', 'pipe', 'pipe'],
-      timeout: 30000,
+      timeout: GENERATOR_SCRIPT_TIMEOUT_MS,
     });
     return { code: 0, stdout, stderr: '' };
   } catch (err) {
diff --git a/tests/gen-section-manifest.test.cjs b/tests/gen-section-manifest.test.cjs
index 5e33c9612..e773a539f 100644
--- a/tests/gen-section-manifest.test.cjs
+++ b/tests/gen-section-manifest.test.cjs
@@ -22,6 +22,7 @@ const path = require('node:path');
 const { execFileSync } = require('node:child_process');
 
 const { createTempDir, cleanup } = require('./helpers.cjs');
+const { GENERATOR_SCRIPT_TIMEOUT_MS } = require('./helpers/timeouts.cjs');
 const {
   buildFreshManifest,
   writeManifestAtomically,
@@ -90,7 +91,7 @@ function runGenSectionManifest(args, cwd = ROOT) {
       cwd,
       encoding: 'utf8',
       stdio: ['pipe', 'pipe', 'pipe'],
-      timeout: 30000,
+      timeout: GENERATOR_SCRIPT_TIMEOUT_MS,
     });
     return { code: 0, stdout, stderr: '' };
   } catch (err) {
diff --git a/tests/gen-state-md-docs.test.cjs b/tests/gen-state-md-docs.test.cjs
index aef7c3ac6..dc813ef6d 100644
--- a/tests/gen-state-md-docs.test.cjs
+++ b/tests/gen-state-md-docs.test.cjs
@@ -27,6 +27,7 @@ const path = require('node:path');
 
 const { createTempDir, cleanup } = require('./helpers.cjs');
 const { runNode } = require('./helpers/process-seam.cjs');
+const { GENERATOR_SCRIPT_TIMEOUT_MS } = require('./helpers/timeouts.cjs');
 const gen = require('../scripts/gen-state-md-docs.cjs');
 const { splitLines, detectEol, joinLines } = require('../gsd-core/bin/lib/text-lines.cjs');
 
@@ -46,7 +47,7 @@ function seedCleanTree(dir) {
 function runGen(args, root) {
   const fullArgs = [SCRIPT, ...args];
   if (root !== undefined) fullArgs.push('--root', root);
-  const r = runNode(fullArgs, { timeoutMs: 30000 });
+  const r = runNode(fullArgs, { timeoutMs: GENERATOR_SCRIPT_TIMEOUT_MS });
   return { code: r.exitCode, stdout: r.stdout, stderr: r.stderr };
 }
 
diff --git a/tests/helpers/timeouts.cjs b/tests/helpers/timeouts.cjs
index 2133b616e..ac07fd47b 100644
--- a/tests/helpers/timeouts.cjs
+++ b/tests/helpers/timeouts.cjs
@@ -224,6 +224,47 @@ const SCAN_USAGE_ERROR_TIMEOUT_MS = 5000;
  */
 const MALFORMED_INPUT_HOOK_TIMEOUT_MS = 5000;
 
+/**
+ * A single `scripts/*.cjs` generator or lint script (gen-adr-index.cjs,
+ * check-glossary-refs.cjs, gen-context-index.cjs, and siblings), spawned
+ * directly and once against a small temp fixture repo -- no fan-out.
+ *
+ * Deliberately NOT `BUILD_TIMEOUT_MS`, despite the coincidentally-matching
+ * value: that constant's own doc comment scopes it specifically to
+ * `scripts/build-hooks.js` ("not a full project build"), and none of this
+ * norm's sites run that script. Reusing a constant for its number while
+ * ignoring what its comment actually describes is exactly the trap this
+ * migration exists to avoid -- see `SEAM_DEFAULT_TIMEOUT_MS` and
+ * `SCAN_USAGE_ERROR_TIMEOUT_MS` for the same reasoning applied elsewhere in
+ * this file.
+ *
+ * Shared across 7 files in batch #4520 of the ad hoc timeout literal
+ * migration, epic #4445 -- every site independently arrived at this exact
+ * value -- that is why it lives here rather than as a file-local constant.
+ */
+const GENERATOR_SCRIPT_TIMEOUT_MS = 30000;
+
+/**
+ * A git plumbing command (or a short scratch-index sequence of them) run
+ * against the REAL, current repo tree -- never a throwaway mkdtemp fixture.
+ * Distinct from `GIT_TIMEOUT_MS` (15000ms, plumbing reads against a small
+ * fixture repo) and `GIT_FIXTURE_TIMEOUT_MS` (60000ms, the shared helper's
+ * own multi-spawn fixture-CONSTRUCTION sequence) -- this norm's sites
+ * either read the real object database directly (`git ls-files`) or build a
+ * synthetic commit on a scratch index against it, which is heavier than a
+ * tiny-fixture read but not the shared helper's own six-spawn construction
+ * class. Explicitly NOT for fixture-repo CONSTRUCTION (init/config/add/commit
+ * against a throwaway mkdtemp repo) -- tests/emitted-attribution.test.cjs's
+ * own file-local `FRESH_FIXTURE_GIT_TIMEOUT_MS` covers that shape instead,
+ * after an earlier pass conflated the two and a Standards-axis review caught
+ * it.
+ *
+ * Shared across 2 files in batch #4520 of the ad hoc timeout literal
+ * migration, epic #4445 -- every site independently arrived at this exact
+ * value -- that is why it lives here rather than as a file-local constant.
+ */
+const REAL_REPO_GIT_TIMEOUT_MS = 30000;
+
 module.exports = {
   PROBE_TIMEOUT_MS,
   HOOK_FANOUT_TIMEOUT_MS,
@@ -238,4 +279,6 @@ module.exports = {
   LOOP_HOOK_POINT_CLI_TIMEOUT_MS,
   SCAN_USAGE_ERROR_TIMEOUT_MS,
   MALFORMED_INPUT_HOOK_TIMEOUT_MS,
+  GENERATOR_SCRIPT_TIMEOUT_MS,
+  REAL_REPO_GIT_TIMEOUT_MS,
 };
diff --git a/tests/lint-docs-command-form.test.cjs b/tests/lint-docs-command-form.test.cjs
index 072475fb2..5517e838f 100644
--- a/tests/lint-docs-command-form.test.cjs
+++ b/tests/lint-docs-command-form.test.cjs
@@ -19,6 +19,7 @@ const os = require('node:os');
 const path = require('node:path');
 const { runNode } = require('./helpers/process-seam.cjs');
 const { gitOrThrow } = require('./helpers/git-fixture.cjs');
+const { GENERATOR_SCRIPT_TIMEOUT_MS } = require('./helpers/timeouts.cjs');
 
 const GUARD_SCRIPT = path.resolve(__dirname, '..', 'scripts', 'lint-docs-command-form.cjs');
 
@@ -60,7 +61,7 @@ function runGuard(cwd) {
   const r = runNode([GUARD_SCRIPT], {
     cwd,
     env: { ...process.env, GSD_LINT_DOCS_COMMAND_FORM_REPO_ROOT: cwd },
-    timeoutMs: 30_000,
+    timeoutMs: GENERATOR_SCRIPT_TIMEOUT_MS,
   });
   return { status: r.exitCode, stdout: r.stdout, stderr: r.stderr };
 }
diff --git a/tests/no-pending-3212-markers.test.cjs b/tests/no-pending-3212-markers.test.cjs
index 4e0a4df43..e4c966435 100644
--- a/tests/no-pending-3212-markers.test.cjs
+++ b/tests/no-pending-3212-markers.test.cjs
@@ -12,6 +12,7 @@ const { test } = require('node:test');
 const assert = require('node:assert/strict');
 const path = require('node:path');
 const { execFileSync } = require('node:child_process');
+const { REAL_REPO_GIT_TIMEOUT_MS } = require('./helpers/timeouts.cjs');
 
 const ROOT = path.resolve(__dirname, '..');
 const MARKER = 'pending #3212';
@@ -38,7 +39,7 @@ function listTrackedFiles() {
   const stdout = execFileSync('git', ['-c', 'safe.directory=*', 'ls-files'], {
     cwd: ROOT,
     encoding: 'utf8',
-    timeout: 30000,
+    timeout: REAL_REPO_GIT_TIMEOUT_MS,
   });
   return stdout
     .split(/\r?\n/)
diff --git a/tests/representative-corpus.test.cjs b/tests/representative-corpus.test.cjs
index 1bc6cf587..bea77e276 100644
--- a/tests/representative-corpus.test.cjs
+++ b/tests/representative-corpus.test.cjs
@@ -49,6 +49,7 @@ const path = require('node:path');
 const { execFileSync } = require('node:child_process');
 
 const { cleanup, TEST_ENV_BASE } = require('./helpers.cjs');
+const { LOOP_HOOK_POINT_CLI_TIMEOUT_MS } = require('./helpers/timeouts.cjs');
 
 const TOOLS_PATH = path.join(__dirname, '..', 'gsd-core', 'bin', 'gsd-tools.cjs');
 const FIXTURES_ROOT = path.join(__dirname, 'fixtures', 'representative');
@@ -59,7 +60,7 @@ function runTools(args, cwd) {
       cwd,
       encoding: 'utf-8',
       env: { ...process.env, ...TEST_ENV_BASE },
-      timeout: 60000,
+      timeout: LOOP_HOOK_POINT_CLI_TIMEOUT_MS,
     });
     return { success: true, output: stdout.trim(), error: '' };
   } catch (err) {