fix: v3.0.7 - restore mandatory first-line badge + pin SKILL_ROOT + add skill-specificity anchor (#278)

Hot-fix for the public v3.0.6 0/8 regression (2026-04-18). Beta went 10/10
yesterday with the same LAW content; public went 0/8 today. The delta was
three structural anchors the port had removed or weakened.

Unit 1 - Restored MANDATORY first-line badge. Every public response now
emits "🌐 last30days v{VERSION} · synced {YYYY-MM-DD}" as line 1, blank
line, then "What I learned:" (GENERAL) or "# {TOPIC_A} vs {TOPIC_B}..."
(COMPARISON). This is the LAW 2 / LAW 4 enforcement anchor that my v3.0.6
port accidentally stripped along with the beta-specific "🧪 last30days-beta"
wording.

Unit 2 - Pinned SKILL_ROOT to the public plugin cache via
`ls -d ~/.claude/plugins/cache/last30days-skill/last30days/*/ | sort -V |
tail -1`, with a small fallback for repo/Gemini/Codex hosts. Replaces the
path-discovery loop that was landing on stale copies (~/.openclaw/,
~/.agents/, ~/.codex/) on machines with a private-repo sync history.

Unit 3 - Added a "SKILL CONTRACT" preface at the top of SKILL.md that names
the 0/8 regression as a documented failure mode and explicitly tells the
model not to treat /last30days as a generic keyword. Encodes user theory
that "/last30days-beta" sounded specific enough to trigger skill-follow
mode while "/last30days" reads as a search term and triggers improvise
mode.

Validation: all three anchors visible in the grep check for public
v3.0.7 cache. Next validation is manual re-run of the 8 failure topics
on public after shipping.

Co-authored-by: Matt Van Horn <455140+mvanhorn@users.noreply.github.com>
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.claude-plugin/plugin.json

@@ -1,6 +1,6 @@
 {
   "name": "last30days",
-  "version": "3.0.6",
+  "version": "3.0.7",
   "description": "Research any topic across Reddit, X, YouTube, TikTok, Instagram, Hacker News, Polymarket, GitHub, and 5+ more sources. AI agent scores by upvotes, likes, and real money - not editors.",
   "author": {
     "name": "Matt Van Horn",