feat: SELECTIVE EXPANSION + smarter ship gates (v0.5.3) (#134)

* feat: SELECTIVE EXPANSION mode + user control for CEO review

Add 4th mode to /plan-ceo-review: SELECTIVE EXPANSION holds current scope
as baseline but surfaces expansion opportunities one by one for cherry-picking.
All modes now present every scope-expanding idea as individual AskUserQuestion
calls — user opts in or out of each one. EXPANSION recommends enthusiastically,
SELECTIVE recommends neutrally. CEO plan persistence writes decisions to disk.

* feat: review dashboard — eng required, CEO/design optional

Only Eng Review gates shipping. CEO Review recommended for big product
changes, Design Review for UI work — both informational only. Adds
skip_eng_review global config to disable the gate entirely.

* chore: bump version and changelog (v0.5.3)

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

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Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

ship/SKILL.md.tmpl

@@ -54,10 +54,11 @@ You are running the `/ship` workflow. This is a **non-interactive, fully automat
 
 {{REVIEW_DASHBOARD}}
 
-If the verdict is NOT "CLEARED TO SHIP (3/3)", use AskUserQuestion:
-- Show which reviews are missing or have open issues
-- RECOMMENDATION: Choose B (run missing reviews first) unless the change is trivial
-- Options: A) Ship anyway  B) Abort — run missing review(s) first  C) Reviews not relevant for this change
+If the verdict is NOT "CLEARED", use AskUserQuestion:
+- Show that Eng Review is missing or has open issues
+- RECOMMENDATION: Choose B (run eng review first) unless the change is obviously trivial (<20 lines, typo fix, config-only)
+- Options: A) Ship anyway  B) Abort — run /plan-eng-review first  C) Change is too small to need eng review
+- If CEO/Design reviews are missing, mention them as informational ("CEO Review not run — recommended for product changes") but do NOT block or recommend aborting for them
 
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