chore(release): v3.3.0

~75 PRs merged since v3.2.0 plus 7 community fixes salvaged via PR triage.

Highlights:
- Install everywhere: npx skills add is canonical for Claude Code, Codex,
  Cursor, Gemini CLI, Copilot, Windsurf, and 50+ Agent Skills hosts.
- New emit mode: --emit=html for shareable HTML briefs.
- New source: Digg (auto-enabled when digg-pp-cli on PATH).
- New env vars: EXCLUDE_SOURCES, LAST30DAYS_YOUTUBE_SSH_HOST.
- New credential source: macOS Keychain.
- Reliability sweep: Reddit (4xx + URL prefix + multi-key auth), xAI
  error surfacing, Windows compatibility, YouTube/HN unblock,
  HTTP retries, planner gating, render fixes.
- Multi-harness reframe: AGENTS.md becomes canonical, CLAUDE.md points
  at it. SKILL_ROOT → SKILL_DIR substitution.

Breaking:
- .codex-plugin/plugin.json removed. Codex installs via npx skills add.

.claude-plugin/plugin.json

@@ -1,6 +1,6 @@
 {
   "name": "last30days",
-  "version": "3.2.4",
+  "version": "3.3.0",
   "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",