fix: per-entity Step 0.55, LAW 7 sub-run quiet, default 2, canonical SKILL.md (#311)

Four fixes based on 2026-04-22 test-window feedback on v3.0.11 --competitors:

- Each competitor sub-run now runs Step 0.55 (X handle / subreddits /
  GitHub) via resolve.auto_resolve inside the fanout closure. Deep-copied
  config per entity prevents _auto_resolve_context leak across sub-runs.
  Resolved data stored on report.artifacts["resolved"] for the renderer.
- New internal_subrun keyword on planner.plan_query and pipeline.run
  suppresses the LAW 7 "No --plan passed" stderr for engine-internal
  fan-out only. Default path unchanged.
- Default --competitors count is now 2 (3-way total). --competitors=N
  still customizes; range 1..6.
- SKILL.md STEP 0 canonical-path self-check forces readers who loaded
  from marketplaces/ (auto-restored to origin/main, stale) to re-read
  from plugins/cache/last30days-skill/last30days/{VERSION}/SKILL.md.
  Two of three 2026-04-22 test windows hit this stale-path trap.
- New ## Resolved Entities block in render_comparison_multi shows
  per-entity handles/subs/github for debug visibility.

Bumps plugin.json to 3.0.12. 12 new tests; 1,175 total passing.

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": "3.0.11",
+  "version": "3.0.12",
   "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",