Add 'what's next' section to /status skill

[sebastientaggart]

Add a priority-ordered "What's next" suggestion to the /status skill output that reads local git state and GitHub data to recommend the logical next workflow step.

Changes

• skills/status.md — New Step 6 with 7 priority-ordered conditions (uncommitted changes → /submit-for-review, approved PR → /deploy, unreleased commits → /deploy, nothing in progress → /start, etc.)
• docs/skills/status.md — Document the new "What's next" section
• ROADMAP.md — Add three future /status enhancement ideas: PR health indicators, stale work detection, /status --team

Issue #39

[sebastientaggart]

Review Summary

Verdict: APPROVE

Findings

• [NOTE] In skills/status.md, the "Do not post, comment, write files, or take any action. Output only." instruction at the end of Step 5 (line 114) sits immediately before the new Step 6. This is pre-existing text and refers to the skill's read-only contract (not "stop processing"), but a future reader could misread it as "skip Step 6." Consider moving that sentence to the Hard Rules section where the same constraint already lives — low priority, not blocking.

• [NOTE] The priority table in Step 6b is well-ordered: P6 ("no open PRs, no open issues") correctly excludes the case where open issues exist, allowing P7 to fire. Logic is sound.

No issues found with correctness, security, or conventions. The skill prompt, docs, and roadmap changes are internally consistent. The removal of the "Never suggest what the developer should work on next" hard rule is intentional and necessary for this feature.