feat(spec): expansions — flags, archive, quality gate, plan-mode-aware Phase 5, /ship integration, tests

Builds on the @jayzalowitz foundation (commit a4e6ee38) with the full
expansion set from CEO + Eng + DX review (24 user decisions + 23 of 28
codex adversarial findings).

spec/SKILL.md.tmpl additions:
- Flag reference table (--dedupe / --no-gate / --audit / --execute /
  --no-execute / --file-only / --plan-file / --sync-archive).
- Phase 1b --dedupe (default ON): gh issue list --search with graceful
  skip on gh-not-installed / unauthed / rate-limited / other errors.
  AskUserQuestion when matches found (merge / file-new / cancel).
- Phase 3 HARD requirement: agent MUST grep/read at least one piece of
  evidence before asking. Project-level fallback prose for prompts with
  no concrete file mapping. Greenfield escape clause.
- Phase 4.5 quality gate (default ON): codex adversarial dispatch with
  fail-closed redaction (AWS/GitHub/Anthropic/OpenAI/private-key regex),
  hard <<<USER_SPEC>>> delimiters + instruction boundary (prompt-injection
  defense), score 0-10 with <7 block, up to 3 iterations, AskUserQuestion
  escape on persistent <7 (ship anyway / save draft / one more try).
- Phase 5 plan-mode-aware dispatch: reads GSTACK_PLAN_MODE env. Active
  → file-only + load into plan file. Inactive → file + --execute spawn
  by default. CLI overrides for explicit control.
- Archive block via eval $(gstack-paths) → $GSTACK_STATE_ROOT/projects/
  $SLUG/specs/<datetime>-<pid>-<slug>.md. Atomic .tmp/mv write. Sync
  excluded by default; --sync-archive to opt in.
- --execute path: dirty-worktree gate (porcelain check + 3-option AUQ
  continue/stash/cancel), TOCTOU re-check after AUQ answer, SHA pin
  via git rev-parse HEAD, unique branch spec/<slug>-$$ + PID-suffixed
  worktree, mandatory final-confirm gate, stash policy with restore
  safety (preserve ref, never auto-drop).
- TTHW timestamps captured at Phase 1 / first citation / file-or-spawn,
  emitted as ttfc_ms + tthw_ms in preamble telemetry envelope.

Cross-system plumbing:
- scripts/resolvers/preamble/generate-preamble-bash.ts: emit
  GSTACK_PLAN_MODE=active|inactive based on CLAUDE_PLAN_FILE presence.
- scripts/resolvers/preamble/generate-routing-injection.ts: add /spec
  to the routing block injected into project CLAUDE.md.
- ship/SKILL.md.tmpl: new "Linked Spec" PR-body section. Reads archive
  frontmatter spec_issue_number and adds Closes #N when full delivery
  confirmed by existing plan-completion gate (codex F4 — conditional).
  Branch-name inference NOT used (codex F3 — fragile under rebase).

Tests (W7):
- test/spec-template-invariants.test.ts: 35 deterministic assertions
  covering Phase 1 hard gate, Phase 3 hard-grep mandate, --dedupe
  graceful-skip paths, --execute race + security hardening (TOCTOU,
  SHA pin, unique branch), quality-gate redaction + BLOCKED path,
  archive atomic write + sync exclusion, plan-mode-aware Phase 5.
- test/spec-template-sync.test.ts: regen + byte-identical check.
- test/skill-e2e-spec-execute.test.ts (periodic-tier scaffold).
- test/skill-llm-eval-spec.test.ts (periodic-tier scaffold).
- test/helpers/touchfiles.ts: register both periodics in E2E_TIERS +
  LLM_JUDGE_TOUCHFILES.

37/37 /spec tests pass. Full bun test exit 0 (pre-existing
url-validation timeout unrelated to /spec).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

scripts/resolvers/preamble/generate-preamble-bash.ts

@@ -90,6 +90,19 @@ _CHECKPOINT_MODE=$(${ctx.paths.binDir}/gstack-config get checkpoint_mode 2>/dev/
 _CHECKPOINT_PUSH=$(${ctx.paths.binDir}/gstack-config get checkpoint_push 2>/dev/null || echo "false")
 echo "CHECKPOINT_MODE: $_CHECKPOINT_MODE"
 echo "CHECKPOINT_PUSH: $_CHECKPOINT_PUSH"
+# Plan-mode hint for skills like /spec that branch behavior on plan-mode state.
+# Claude Code exposes plan mode via system reminders; we detect best-effort
+# from CLAUDE_PLAN_FILE (set by the harness when plan mode is active) and
+# fall back to "inactive". Codex hosts and Claude execution mode both end up
+# inactive, which is the safe default (defaults to file+execute pipeline).
+if [ -n "\${CLAUDE_PLAN_FILE:-}\${GSTACK_PLAN_MODE_FORCE:-}" ]; then
+  export GSTACK_PLAN_MODE="active"
+elif [ "\${GSTACK_PLAN_MODE:-}" = "active" ]; then
+  export GSTACK_PLAN_MODE="active"
+else
+  export GSTACK_PLAN_MODE="inactive"
+fi
+echo "GSTACK_PLAN_MODE: $GSTACK_PLAN_MODE"
 [ -n "$OPENCLAW_SESSION" ] && echo "SPAWNED_SESSION: true" || true${ctx.host === 'gbrain' || ctx.host === 'hermes' ? `
 if command -v gbrain &>/dev/null; then
   _BRAIN_JSON=$(gbrain doctor --fast --json 2>/dev/null || echo '{}')

scripts/resolvers/preamble/generate-routing-injection.ts

@@ -33,6 +33,7 @@ Key routing rules:
 - Ship/deploy/PR → invoke /ship or /land-and-deploy
 - Save progress → invoke /context-save
 - Resume context → invoke /context-restore
+- Author a backlog-ready spec/issue → invoke /spec
 \`\`\`
 
 Then commit the change: \`git add CLAUDE.md && git commit -m "chore: add gstack skill routing rules to CLAUDE.md"\`