fix: dynamic base branch detection across all SKILL templates (v0.3.10) (#81)

* feat: add {{BASE_BRANCH_DETECT}} resolver to gen-skill-docs

DRY placeholder for dynamic base branch detection across PR-targeting
skills. Detects via gh pr view (existing PR base) → gh repo view
(repo default) → fallback to main.

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

* fix: ship skill detects base branch instead of hardcoding main

Replaces ~14 hardcoded 'main' references with dynamic detection via
{{BASE_BRANCH_DETECT}}. Fixes stacked branches and Conductor workspaces
targeting non-main branches. Adds --base <base> to gh pr create.

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

* fix: review, qa, plan-ceo-review detect base branch dynamically

Same pattern as ship: replaces hardcoded 'main' with {{BASE_BRANCH_DETECT}}.
Also cleans up qa bash-isms (REPORT_DIR variable, port chaining).

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

* fix: retro detects default branch instead of hardcoding origin/main

Retro queries commit history (not PR targets), so uses simpler detection:
gh repo view defaultBranchRef. Replaces ~11 origin/main refs with
origin/<default>.

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

* docs: add explicit cross-step references in gstack-upgrade template

Bash blocks are self-contained, but cross-block variable references
(INSTALL_DIR from Step 2) were implicit. Adds prose making them explicit.

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

* docs+test: SKILL authoring guidance + regression tests

Adds "Writing SKILL templates" section to CLAUDE.md explaining that
templates are prompts, not scripts. Adds validation test catching
hardcoded 'main' in git commands, and resolver content test.

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

* docs: update ARCHITECTURE + CONTRIBUTING for new placeholders

Add {{BASE_BRANCH_DETECT}} to ARCHITECTURE.md placeholder list.
Cross-reference CLAUDE.md template authoring guidance from CONTRIBUTING.md.

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

* chore: bump version and changelog (v0.3.10)

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

* fix: add missing blank line between resolver functions

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

* test: add 3 E2E smoke tests for base branch detection

- /review: verifies Step 0 detection + git diff against detected base
- /ship: truncated dry-run (Steps 0-1 only, no push/PR), asserts no
  destructive actions
- /retro: verifies default branch detection for git log queries

Covers the {{BASE_BRANCH_DETECT}} resolver path (review), the ship
template's dual abort check, and retro's inline detection pattern.

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

* chore: bump version and changelog (v0.4.2)

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

---------

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

scripts/gen-skill-docs.ts

@@ -174,6 +174,27 @@ If \`NEEDS_SETUP\`:
 3. If \`bun\` is not installed: \`curl -fsSL https://bun.sh/install | bash\``;
 }
 
+function generateBaseBranchDetect(): string {
+  return `## Step 0: Detect base branch
+
+Determine which branch this PR targets. Use the result as "the base branch" in all subsequent steps.
+
+1. Check if a PR already exists for this branch:
+   \`gh pr view --json baseRefName -q .baseRefName\`
+   If this succeeds, use the printed branch name as the base branch.
+
+2. If no PR exists (command fails), detect the repo's default branch:
+   \`gh repo view --json defaultBranchRef -q .defaultBranchRef.name\`
+
+3. If both commands fail, fall back to \`main\`.
+
+Print the detected base branch name. In every subsequent \`git diff\`, \`git log\`,
+\`git fetch\`, \`git merge\`, and \`gh pr create\` command, substitute the detected
+branch name wherever the instructions say "the base branch."
+
+---`;
+}
+
 function generateQAMethodology(): string {
   return `## Modes
 
@@ -455,6 +476,7 @@ const RESOLVERS: Record<string, () => string> = {
   SNAPSHOT_FLAGS: generateSnapshotFlags,
   PREAMBLE: generatePreamble,
   BROWSE_SETUP: generateBrowseSetup,
+  BASE_BRANCH_DETECT: generateBaseBranchDetect,
   QA_METHODOLOGY: generateQAMethodology,
 };