feat(linkedin): generate iCal file during batch creation

Step 5b in batch.md generates a .ics calendar file from the queue,
giving users 15-minute reminders in their calendar app before each
scheduled post. Supports macOS Calendar, Google Calendar, Outlook.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

plugins/linkedin-thought-leadership/commands/batch.md

@@ -168,6 +168,38 @@ Mark as published: /linkedin:publish
 Remember: Run 5x5x5 engagement 15 min before each post!
 ```
 
+### 5b. Generate Calendar File
+
+Generate a .ics calendar file so the user can import posting reminders into their calendar app:
+
+```bash
+node --input-type=module -e "
+import { queueUpcoming } from '${CLAUDE_PLUGIN_ROOT}/hooks/scripts/queue-manager.mjs';
+import { generateIcalFromQueue, writeIcalFile } from '${CLAUDE_PLUGIN_ROOT}/hooks/scripts/ical-generator.mjs';
+const upcoming = queueUpcoming(14);
+if (upcoming.length === 0) { console.log('No upcoming posts to schedule.'); process.exit(0); }
+const events = generateIcalFromQueue(upcoming);
+const icsPath = '${CLAUDE_PLUGIN_ROOT}/assets/drafts/week-[WXX]/schedule.ics';
+writeIcalFile(icsPath, events);
+console.log('Calendar file: ' + icsPath + ' (' + events.length + ' events)');
+"
+```
+
+Replace `[WXX]` with the actual ISO week number used for the batch directory.
+
+Show the user:
+
+```
+Calendar file generated: assets/drafts/week-[WXX]/schedule.ics
+
+Import this file into your calendar app:
+- macOS: Double-click the .ics file → Calendar.app imports it
+- Google Calendar: Settings → Import → select .ics file
+- Outlook: File → Open → Import → .ics file
+
+Each scheduled post has a 15-minute reminder before posting time.
+```
+
 ## Reference Files
 
 - `${CLAUDE_PLUGIN_ROOT}/references/thought-leadership-angles.md`