test(#4515): migrate installer-runs batch to named timeout constants (#4575)

* test(#4515): migrate installer-runs batch to named timeout constants

Batch 4 of the ad hoc timeout literal migration (epic #4445). Replaces
every bare numeric timeout/timeoutMs object-literal property across
tests/install.test.cjs, tests/install-minimal-hooks.test.cjs,
tests/fragment-single-edit-propagation.install.test.cjs,
tests/install-regressions.test.cjs, tests/install-runtime-artifacts.test.cjs,
tests/npm-integrity-gate.test.cjs, tests/faulty-deps.test.cjs,
tests/release-tarball-smoke.install.test.cjs,
tests/install-write-confinement.test.cjs, tests/plugin-manifest.test.cjs,
and tests/packaging-shipped-scripts-require-only-shipped.test.cjs with a
named constant, per eslint-rules/no-adhoc-timeout-literal.cjs. Removes
these 11 files from the rule's allowlist.

Adds one new shared constant to tests/helpers/timeouts.cjs for a
fixture-JSON value (in seconds, not ms) mimicking a Claude Code
settings.json hook-entry's own timeout field, shared across two files in
this batch. Every other new constant is file-local, each carrying a
comment explaining why its call site is a distinct operational class from
the existing shared norms even where its digits numerically coincide with
one. No src/bin file touched, no numeric timeout value changed anywhere.

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

* fix: combine gsd-worktree-path-guard's git rev-parse calls to cut subprocess count under CI load

Discovered while verifying PR #4575 (a full test (windows-latest) failure in an unrelated test, tests/kilo-upgrades.test.cjs's worktree-path-guard rejection test). Root cause: this hook's up-to-4 sequential git spawns (git-dir, branch, worktree-toplevel, file-toplevel), invoked inside a native-plugin's own 8000ms-capped subprocess wrapper, left zero margin for node/git startup overhead — the guard is deliberately fail-open on any timeout, so CI-load-induced latency in this chain silently downgrades a security block into an allow. Combines the first three git rev-parse calls (git-dir, branch via --abbrev-ref, worktree-toplevel) into ONE spawn instead of three, using git's documented multi-flag rev-parse output (one line per flag, in order) — verified empirically including the detached-HEAD edge case. No timeout value changed; this reduces subprocess COUNT, not any tolerance.

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

* docs: add changeset fragment for the worktree-path-guard fix

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

---------

Co-authored-by: sim <sim@local>
Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>

tests/helpers/timeouts.cjs

@@ -127,6 +127,20 @@ const SEAM_DEFAULT_TIMEOUT_MS = 60000;
  */
 const QUICK_SPAWN_TIMEOUT_MS = 10000;
 
+/**
+ * NOT a subprocess spawn timeout. This is fixture DATA -- the numeric value
+ * placed inside a fixture JSON object that mimics a Claude Code
+ * `settings.json` hook-entry's own `timeout` field, whose schema expresses
+ * that field in SECONDS. Do not pass this into a `spawnSync`/`execFileSync`
+ * options object -- every other constant in this file is milliseconds, this
+ * one is not.
+ *
+ * Shared across >=2 files in batch #4515 of the ad hoc timeout literal
+ * migration, epic #4445 -- that is why it lives here rather than as a
+ * file-local constant.
+ */
+const FIXTURE_HOOK_TIMEOUT_SECONDS = 5;
+
 module.exports = {
   PROBE_TIMEOUT_MS,
   HOOK_FANOUT_TIMEOUT_MS,
@@ -136,4 +150,5 @@ module.exports = {
   INSTALL_TIMEOUT_MS,
   SEAM_DEFAULT_TIMEOUT_MS,
   QUICK_SPAWN_TIMEOUT_MS,
+  FIXTURE_HOOK_TIMEOUT_SECONDS,
 };