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/week-rollover.mjs

@@ -0,0 +1,49 @@
+// Pure function for week-rollover logic.
+// Exported separately for testability.
+
+/**
+ * Apply week rollover to state file content.
+ * Returns updated content string if rollover was applied, null otherwise.
+ *
+ * @param {string} stateContent - Full state file content (with YAML frontmatter)
+ * @param {string} currentWeek - Week value from state file (e.g. "2026-W14")
+ * @param {string} actualWeek - Computed current ISO week (e.g. "2026-W15")
+ * @returns {{ content: string, message: string } | null}
+ */
+export function applyWeekRollover(stateContent, currentWeek, actualWeek) {
+  if (!actualWeek) return null;
+
+  // Case 1: current_week is empty — initialize without resetting posts
+  if (!currentWeek) {
+    const updated = stateContent.replace(
+      /^current_week: .*/m,
+      `current_week: "${actualWeek}"`
+    );
+    if (updated === stateContent) return null;
+    return {
+      content: updated,
+      message: `Initialized current_week to ${actualWeek}.`
+    };
+  }
+
+  // Case 2: week matches — no action needed
+  if (currentWeek === actualWeek) return null;
+
+  // Case 3: week changed — reset posts_this_week and update current_week
+  let updated = stateContent;
+  updated = updated.replace(
+    /^posts_this_week: .*/m,
+    'posts_this_week: 0'
+  );
+  updated = updated.replace(
+    /^current_week: .*/m,
+    `current_week: "${actualWeek}"`
+  );
+
+  if (updated === stateContent) return null;
+
+  return {
+    content: updated,
+    message: `Auto-reset: posts_this_week → 0 for new week ${actualWeek} (was ${currentWeek}).`
+  };
+}