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>

TODOS.md

@@ -342,6 +342,18 @@ Linux cookie import shipped in v0.11.11.0 (Wave 3). Supports Chrome, Chromium, B
 
 
 
+### Extend worktree isolation to Claude E2E tests
+
+**What:** Add `useWorktree?: boolean` option to `runSkillTest()` so any Claude E2E test can opt into worktree mode for full repo context instead of tmpdir fixtures.
+
+**Why:** Some Claude E2E tests (CSO audit, review-sql-injection) create minimal fake repos but would produce more realistic results with full repo context. The infrastructure exists (`describeWithWorktree()` in e2e-helpers.ts) — this extends it to the session-runner level.
+
+**Context:** WorktreeManager shipped in v0.11.12.0. Currently only Gemini/Codex tests use worktrees. Claude tests use planted-bug fixture repos which are correct for their purpose, but new tests that want real repo context can use `describeWithWorktree()` today. This TODO is about making it even easier via a flag on `runSkillTest()`.
+
+**Effort:** M (human: ~2 days / CC: ~20 min)
+**Priority:** P3
+**Depends on:** Worktree isolation (shipped v0.11.12.0)
+
 ### E2E model pinning — SHIPPED
 
 ~~**What:** Pin E2E tests to claude-sonnet-4-6 for cost efficiency, add retry:2 for flaky LLM responses.~~