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/hooks/scripts/pre-compact.mjs

@@ -0,0 +1,29 @@
+#!/usr/bin/env node
+// pre-compact.mjs
+// PreCompact hook for linkedin-studio plugin
+// Reminds Claude to preserve critical LinkedIn session context before compaction
+//
+// Exit codes:
+//   0 - Always allow (informational hook)
+
+const context = [
+  'Before compacting context, preserve these critical LinkedIn session details:',
+  '- Current post draft (full text if in progress)',
+  '- Chosen angle and format',
+  '- User feedback and iteration direction',
+  '- Quality check results',
+  '- State file values (streak, weekly count, last post date)',
+  '- Any planned topics or next steps',
+  'Ensure these survive the context compaction.',
+].join('\n');
+
+const output = {
+  continue: true,
+  hookSpecificOutput: {
+    hookEventName: 'PreCompact',
+    additionalContext: context,
+  },
+};
+
+process.stdout.write(JSON.stringify(output));
+process.exit(0);