refactor: use INVOKE_SKILL resolver for plan-ceo-review office-hours fallback

Replace inline skill loading prose (read file, skip sections) with
{{INVOKE_SKILL:office-hours}} in the mid-session detection path.
The BENEFITS_FROM prerequisite offer is unchanged (separate use case).

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

plan-ceo-review/SKILL.md

@@ -564,12 +564,27 @@ sure," or is clearly exploring rather than reviewing — offer `/office-hours`:
 Options: A) Yes, run /office-hours now. B) No, keep going.
 If they keep going, proceed normally — no guilt, no re-asking.
 
-If they choose A: Read the office-hours skill file from disk:
-`~/.claude/skills/gstack/office-hours/SKILL.md`
+If they choose A:
 
-Follow it inline, skipping these sections (already handled by parent skill):
-Preamble, AskUserQuestion Format, Completeness Principle, Search Before Building,
-Contributor Mode, Completion Status Protocol, Telemetry.
+Read the `/office-hours` skill file at `~/.claude/skills/gstack/office-hours/SKILL.md` using the Read tool.
+
+**If unreadable:** Skip with "Could not load /office-hours — skipping." and continue.
+
+Follow its instructions from top to bottom, **skipping these sections** (already handled by the parent skill):
+- Preamble (run first)
+- AskUserQuestion Format
+- Completeness Principle — Boil the Lake
+- Search Before Building
+- Contributor Mode
+- Completion Status Protocol
+- Telemetry (run last)
+- Step 0: Detect platform and base branch
+- Review Readiness Dashboard
+- Plan File Review Report
+- Prerequisite Skill Offer
+- Plan Status Footer
+
+Execute every other section at full depth. When the loaded skill's instructions are complete, continue with the next step below.
 
 Note current Step 0A progress so you don't re-ask questions already answered.
 After completion, re-run the design doc check and resume the review.

plan-ceo-review/SKILL.md.tmpl

@@ -143,12 +143,9 @@ sure," or is clearly exploring rather than reviewing — offer `/office-hours`:
 Options: A) Yes, run /office-hours now. B) No, keep going.
 If they keep going, proceed normally — no guilt, no re-asking.
 
-If they choose A: Read the office-hours skill file from disk:
-`~/.claude/skills/gstack/office-hours/SKILL.md`
+If they choose A:
 
-Follow it inline, skipping these sections (already handled by parent skill):
-Preamble, AskUserQuestion Format, Completeness Principle, Search Before Building,
-Contributor Mode, Completion Status Protocol, Telemetry.
+{{INVOKE_SKILL:office-hours}}
 
 Note current Step 0A progress so you don't re-ask questions already answered.
 After completion, re-run the design doc check and resume the review.