chore: add Gemini config, Jamie Instagram caption guide, merge settings

- Add .gemini/settings.json for Gemini CLI
- Add Jamie Instagram caption style guide (v1.0)
- Merge conflict in settings.local.json (both upstream and local permissions)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gemini/settings.json

@@ -0,0 +1,5 @@
+{
+  "general": {
+    "previewFeatures": true
+  }
+}