fix: restore v0.4.2 changelog entries lost during cherry-pick conflict

The base branch detection entries from main were dropped when resolving
the CHANGELOG conflict — should have merged both sets, not replaced.

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

CHANGELOG.md

@@ -4,6 +4,10 @@
 
 - **`$B js "await fetch(...)"` now just works.** Any `await` expression in `$B js` or `$B eval` is automatically wrapped in an async context. No more `SyntaxError: await is only valid in async functions`. Single-line eval files return values directly; multi-line files use explicit `return`.
 - **Contributor mode now reflects, not just reacts.** Instead of only filing reports when something breaks, contributor mode now prompts periodic reflection: "Rate your gstack experience 0-10. Not a 10? Think about why." Catches quality-of-life issues and friction that passive detection misses. Reports now include a 0-10 rating and "What would make this a 10" to focus on actionable improvements.
+- **Skills now respect your branch target.** `/ship`, `/review`, `/qa`, and `/plan-ceo-review` detect which branch your PR actually targets instead of assuming `main`. Stacked branches, Conductor workspaces targeting feature branches, and repos using `master` all just work now.
+- **`/retro` works on any default branch.** Repos using `master`, `develop`, or other default branch names are detected automatically — no more empty retros because the branch name was wrong.
+- **New `{{BASE_BRANCH_DETECT}}` placeholder** for skill authors — drop it into any template and get 3-step branch detection (PR base → repo default → fallback) for free.
+- **3 new E2E smoke tests** validate base branch detection works end-to-end across ship, review, and retro skills.
 
 ### For contributors
 
@@ -11,6 +15,10 @@
 - Smart eval wrapping: single-line → expression `(...)`, multi-line → block `{...}` with explicit `return`.
 - 6 new async wrapping unit tests, 40 new contributor mode preamble validation tests.
 - Calibration example framed as historical ("used to fail") to avoid implying a live bug post-fix.
+- Added "Writing SKILL templates" section to CLAUDE.md — rules for natural language over bash-isms, dynamic branch detection, self-contained code blocks.
+- Hardcoded-main regression test scans all `.tmpl` files for git commands with hardcoded `main`.
+- QA template cleaned up: removed `REPORT_DIR` shell variable, simplified port detection to prose.
+- gstack-upgrade template: explicit cross-step prose for variable references between bash blocks.
 
 ## 0.4.1 — 2026-03-16