test(#4520): migrate generators/doc-gates/attribution batch to named timeout constants

Batch 9 of 17 in the ad hoc timeout literal migration (epic #4445).
Replaces every bare numeric timeout/timeoutMs object-literal property in
14 files with a named constant, per eslint-rules/no-adhoc-timeout-literal.cjs.
Removes the 14 files from the rule's allowlist.

The issue's own guess ("all run a scripts/*.cjs generator or lint script
once, BUILD_TIMEOUT_MS class") needed two corrections found by reading
every site directly. First, BUILD_TIMEOUT_MS's own doc comment scopes it
specifically to scripts/build-hooks.js, which none of this batch's
generator/lint-script sites run — a new shared constant,
GENERATOR_SCRIPT_TIMEOUT_MS, covers the class instead. Second,
no-pending-3212-markers.test.cjs's single site spawns `git ls-files`
directly, not a scripts/*.cjs script at all — routed to a second new
shared constant, REAL_REPO_GIT_TIMEOUT_MS, promoted once
emitted-attribution.test.cjs's own git-plumbing sites were found sharing
the same class and value.

Isolated Standards-axis review caught a further misclassification: one
of REAL_REPO_GIT_TIMEOUT_MS's three emitted-attribution.test.cjs sites
actually builds a fresh throwaway temp repo (createTempDir + git init),
contradicting that constant's own real-repo-tree-only scope. Fixed with
a new file-local FRESH_FIXTURE_GIT_TIMEOUT_MS holding the exact
pre-existing value under an honest name, rather than reusing the shared
GIT_FIXTURE_TIMEOUT_MS (which would have doubled the bound).

emitted-attribution.test.cjs also gets two more file-local constants:
HEAVY_REAL_TREE_TEST_TIMEOUT_MS (node:test's own per-test timeout
option, not a spawn bound) and BUILD_HOOKS_UNDER_LOAD_TIMEOUT_MS (the
same build-hooks.js script as the shared norm, at 4x its bound inside
the suite's heaviest test). emitted-ack-trailer.test.cjs gets
IMPOSSIBLY_SHORT_GIT_TIMEOUT_MS — the one value in this migration that
is deliberately tiny (20ms), used to force a timeout in a negative test,
not generous headroom.

No src/bin file touched, no numeric value changed anywhere.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

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",