feat: Review Readiness Dashboard + gstack-slug helper (v0.5.1) (#130)

* feat: add bin/gstack-slug helper + migrate all inline SLUG computation

Extract the opaque SLUG sed pipeline into a shared 5-line shell script.
Replace 8 inline copies across templates with eval $(gstack-slug).
Sanitizes branch names (/ → -) to prevent subdirectory creation.

* feat: review readiness dashboard — track CEO/Eng/Design reviews per branch

Each review skill logs its result to JSONL. A shared {{REVIEW_DASHBOARD}}
placeholder displays run counts, timestamps, and a CLEARED TO SHIP verdict.
/ship pre-flight reads the dashboard and prompts when reviews are missing.

* chore: bump version and changelog (v0.5.1)

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

---------

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

qa/SKILL.md

@@ -171,7 +171,7 @@ Before falling back to git diff heuristics, check for richer test plan sources:
 
 1. **Project-scoped test plans:** Check `~/.gstack/projects/` for recent `*-test-plan-*.md` files for this repo
    ```bash
-   SLUG=$(git remote get-url origin 2>/dev/null | sed 's|.*[:/]\([^/]*/[^/]*\)\.git$|\1|;s|.*[:/]\([^/]*/[^/]*\)$|\1|' | tr '/' '-')
+   eval $(~/.claude/skills/gstack/bin/gstack-slug 2>/dev/null)
    ls -t ~/.gstack/projects/$SLUG/*-test-plan-*.md 2>/dev/null | head -1
    ```
 2. **Conversation context:** Check if a prior `/plan-eng-review` or `/plan-ceo-review` produced test plan output in this conversation
@@ -579,7 +579,7 @@ Write the report to both local and project-scoped locations:
 
 **Project-scoped:** Write test outcome artifact for cross-session context:
 ```bash
-SLUG=$(git remote get-url origin 2>/dev/null | sed 's|.*[:/]\([^/]*/[^/]*\)\.git$|\1|;s|.*[:/]\([^/]*/[^/]*\)$|\1|' | tr '/' '-')
+eval $(~/.claude/skills/gstack/bin/gstack-slug 2>/dev/null)
 mkdir -p ~/.gstack/projects/$SLUG
 ```
 Write to `~/.gstack/projects/{slug}/{user}-{branch}-test-outcome-{datetime}.md`