merge: integrate origin/main (v0.18.2.0) — context rot defense for /ship

Main added one commit (#1030, b3eaffce): "context rot defense for /ship —
subagent isolation + clean step numbering (v0.18.2.0)". This restructured
the ship template to:
- Renumber fractional steps (3.47, 8.5, 8.75) to clean integers (1-20)
- Move document-release from post-PR (Step 8.5) to pre-PR subagent
  dispatch (Step 18) so doc sync actually happens
- Wrap 4 heavy sub-workflows (coverage audit, plan completion audit,
  Greptile triage, doc sync) in subagent dispatches for context isolation

Conflicts and resolutions:
- VERSION: kept this branch's 0.19.0.0 (higher than main's 0.18.2.0).
- CHANGELOG.md: kept both entries — 0.19.0.0 on top, 0.18.2.0 below,
  contiguous version sequence preserved.
- ship/SKILL.md.tmpl: integrated this branch's WIP-squash sub-step with
  main's renumbered step structure. My old "Step 5.75: WIP Commit Squash"
  is now "Step 15.0: WIP Commit Squash" — a genuinely-nested sub-step
  inside main's "Step 15: Commit (bisectable chunks)". Per main's note:
  "Resolver sub-steps that are genuinely nested are preserved." Internal
  refs updated (Step 6 → Step 15.1, Step 7 → push step).
- package.json: version mismatch with VERSION caught by gen-skill-docs
  test. Bumped to 0.19.0.0 to match.
- ship/SKILL.md and golden ship fixtures: regenerated via
  `bun run gen:skill-docs --host all` and re-snapshotted for
  claude/codex/factory hosts.

Verification:
- bun test test/gen-skill-docs.test.ts: 348 pass / 0 fail
- bun test test/host-config.test.ts: passes
- bun run gen:skill-docs --host all: completes cleanly

Token-ceiling warnings on plan-ceo-review (29K), office-hours (26K),
ship (35K — grew slightly from main's 34K with the WIP squash addition).
Pre-existing concern, flagged as follow-up, not blocking.

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

test/gen-skill-docs.test.ts

@@ -759,13 +759,13 @@ describe('TEST_COVERAGE_AUDIT placeholders', () => {
 
   test('ship SKILL.md contains review army specialist dispatch', () => {
     expect(shipSkill).toContain('Specialist Dispatch');
-    expect(shipSkill).toContain('Step 3.55');
-    expect(shipSkill).toContain('Step 3.56');
+    expect(shipSkill).toContain('Step 9.1');
+    expect(shipSkill).toContain('Step 9.2');
   });
 
   test('ship SKILL.md contains cross-review finding dedup', () => {
     expect(shipSkill).toContain('Cross-review finding dedup');
-    expect(shipSkill).toContain('Step 3.57');
+    expect(shipSkill).toContain('Step 9.3');
   });
 
   test('ship SKILL.md contains re-run idempotency behavior', () => {
@@ -846,7 +846,7 @@ describe('PLAN_COMPLETION_AUDIT placeholders', () => {
 
   test('ship SKILL.md contains plan completion audit step', () => {
     expect(shipSkill).toContain('Plan Completion Audit');
-    expect(shipSkill).toContain('Step 3.45');
+    expect(shipSkill).toContain('Step 8');
   });
 
   test('review SKILL.md contains plan completion in scope drift', () => {
@@ -895,7 +895,7 @@ describe('PLAN_VERIFICATION_EXEC placeholder', () => {
   const shipSkill = fs.readFileSync(path.join(ROOT, 'ship', 'SKILL.md'), 'utf-8');
 
   test('ship SKILL.md contains plan verification step', () => {
-    expect(shipSkill).toContain('Step 3.47');
+    expect(shipSkill).toContain('Step 8.1');
     expect(shipSkill).toContain('Plan Verification');
   });
 
@@ -953,7 +953,7 @@ describe('Ship metrics logging', () => {
   const shipSkill = fs.readFileSync(path.join(ROOT, 'ship', 'SKILL.md'), 'utf-8');
 
   test('ship SKILL.md contains metrics persistence step', () => {
-    expect(shipSkill).toContain('Step 8.75');
+    expect(shipSkill).toContain('Step 20');
     expect(shipSkill).toContain('coverage_pct');
     expect(shipSkill).toContain('plan_items_total');
     expect(shipSkill).toContain('plan_items_done');