refactor(linkedin)!: rename plugin linkedin-thought-leadership → linkedin-studio (v3.0.0)

BREAKING CHANGE: the marketplace slug, the agent namespace
(linkedin-studio:<agent>), and the runtime state-file path
(~/.claude/linkedin-studio.local.md) all change. Reinstall required;
existing state migrated in place (post metrics, streak, history preserved).
The /linkedin:* commands are unchanged — the command namespace is set
per-command in frontmatter and was always independent of the plugin slug.
Functionality is byte-identical to v2.4.0; this release is pure identity.

- dir + manifests: plugins/linkedin-studio + plugin.json + root marketplace.json
- agent namespace updated in commands/newsletter.md (only functional invoker)
- state path updated in 4 hook scripts + topic-rotation prompt + state template
- catch-all skill dir renamed skills/linkedin-studio (5 functional skills unchanged)
- docs + version bump to 3.0.0 across README badge, CHANGELOG, root README/CLAUDE.md
- historical records (CHANGELOG past entries, docs/ build artifacts,
  config-audit v5.0.0 snapshots) intentionally retain the old slug

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

plugins/linkedin-studio/CONTRIBUTING.md

@@ -0,0 +1,43 @@
+# Contributing to linkedin-studio
+
+This is a solo project. Bug reports and feature requests are welcome, but pull requests are not accepted.
+
+## Reporting bugs
+
+Open an issue with:
+- Plugin version (from `.claude-plugin/plugin.json`)
+- Claude Code version (`claude --version`)
+- What you did, what you expected, what happened instead
+- Whether it fails consistently or occasionally
+
+## Suggesting features or improvements
+
+Open an issue describing:
+- The problem you ran into
+- What you think would solve it
+- Any alternatives you considered
+
+## Design principles
+
+Changes to this plugin must preserve:
+- **Cross-platform** — all hooks are Node.js (.mjs), no bash dependency
+- **Privacy-first** — personal data (voice samples, analytics, queue) stays gitignored
+- **Generalizable** — no hardcoded user identity; templates for personalization
+- **Cost-aware** — Sonnet for most agents, Haiku for lightweight tasks
+- **Algorithm-grounded** — content strategies backed by documented LinkedIn signals
+
+## Testing locally
+
+```bash
+claude plugin add /path/to/linkedin-studio
+
+# In a Claude Code session:
+/linkedin           # Check status and command menu
+/linkedin:quick     # Test quick post flow
+/linkedin:profile   # Test profile audit
+```
+
+For analytics:
+```bash
+cd scripts/analytics && npm install && npm test
+```