feat: worktree isolation for E2E tests + infrastructure elegance (v0.11.12.0) (#425)

* refactor: extract gen-skill-docs into modular resolver architecture

Break the 3000-line monolith into 10 domain modules under scripts/resolvers/:
types, constants, preamble, utility, browse, design, testing, review,
codex-helpers, and index. Each module owns one domain of template generation.

The preamble module introduces a 4-tier composition system (T1-T4) so skills
only pay for the preamble sections they actually need, reducing token usage
for lightweight skills by ~40%.

Adds a token budget dashboard that prints after every generation run showing
per-skill and total token counts.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat: tiered preamble — skills only pay for what they use

Tag all 23 templates with preamble-tier (T1-T4). Lightweight skills
like /browse and /benchmark get a minimal preamble (~40% fewer tokens),
while review skills get the full stack. Regenerate all SKILL.md files.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat: migrate eval storage to project-scoped paths

Move eval results and E2E run artifacts from ~/.gstack-dev/evals/ to
~/.gstack/projects/$SLUG/evals/ so each project's eval history lives
alongside its other gstack data. Falls back to legacy path if slug
detection fails.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: sync package.json version with VERSION after merge

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat: add WorktreeManager for isolated test environments

Reusable platform module (lib/worktree.ts) that creates git worktrees
for test isolation and harvests useful changes as patches. Includes
SHA-256 dedup, original SHA tracking for committed change detection,
and automatic gitignored artifact copying (.agents/, browse/dist/).

12 unit tests covering lifecycle, harvest, dedup, and error handling.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat: integrate worktree isolation into E2E test infrastructure

Add createTestWorktree(), harvestAndCleanup(), and describeWithWorktree()
helpers to e2e-helpers.ts. Add harvest field to EvalTestEntry for
eval-store integration. Register lib/worktree.ts as a global touchfile.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat: run Gemini and Codex E2E tests in worktrees

Switch both test suites from cwd: ROOT to worktree isolation.
Gemini (--yolo) no longer pollutes the working tree. Codex
(read-only) gets worktree for consistency. Useful changes are
harvested as patches for cherry-picking.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: skip symlinks in copyDirSync to prevent infinite recursion

Adversarial review caught that .claude/skills/gstack may be a symlink
back to the repo root, causing copyDirSync to recurse infinitely
when copying gitignored artifacts into worktrees.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* chore: bump version and changelog (v0.11.12.0)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix: relax session-awareness assertion to accept structured options

The LLM consistently presents well-formatted A/B choices with pros/cons
but doesn't always use the exact string "RECOMMENDATION". Accept
case-insensitive "recommend", "option a", "which do you want", or
"which approach" as equivalent signals of a structured recommendation.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -1,5 +1,24 @@
 # Changelog
 
+## [0.11.13.0] - 2026-03-24 — Worktree Isolation + Infrastructure Elegance
+
+### Added
+
+- **E2E tests now run in git worktrees.** Gemini and Codex tests no longer pollute your working tree. Each test suite gets an isolated worktree, and useful changes the AI agent makes are automatically harvested as patches you can cherry-pick. Run `git apply ~/.gstack-dev/harvests/<id>/gemini.patch` to grab improvements.
+- **Harvest deduplication.** If a test keeps producing the same improvement across runs, it's detected via SHA-256 hash and skipped — no duplicate patches piling up.
+- **`describeWithWorktree()` helper.** Any E2E test can now opt into worktree isolation with a one-line wrapper. Future tests that need real repo context (git history, real diff) can use this instead of tmpdirs.
+
+### Changed
+
+- **Gen-skill-docs is now a modular resolver pipeline.** The monolithic 1700-line generator is split into 8 focused resolver modules (browse, preamble, design, review, testing, utility, constants, codex-helpers). Adding a new placeholder resolver is now a single file instead of editing a megafunction.
+- **Eval results are project-scoped.** Results now live in `~/.gstack/projects/$SLUG/evals/` instead of the global `~/.gstack-dev/evals/`. Multi-project users no longer get eval results mixed together.
+
+### For contributors
+
+- WorktreeManager (`lib/worktree.ts`) is a reusable platform module — future skills like `/batch` can import it directly.
+- 12 new unit tests for WorktreeManager covering lifecycle, harvest, dedup, and error handling.
+- `GLOBAL_TOUCHFILES` updated so worktree infrastructure changes trigger all E2E tests.
+
 ## [0.11.12.0] - 2026-03-24 — Triple-Voice Autoplan
 
 Every `/autoplan` phase now gets two independent second opinions — one from Codex (OpenAI's frontier model) and one from a fresh Claude subagent. Three AI reviewers looking at your plan from different angles, each phase building on the last.