fix(reno-stars): default plugins to browser-automation

Every agent in the reno-stars org (marketing, sales, dev, coordinator)
plausibly needs browser access at some point — social posts, GBP edits,
directory submissions, InvoiceSimple publish. Without the plugin on
first import, agents fall back to launching their own Chromium inside
the container, which doesn't have the operator's authenticated Chrome
profile (no logged-in sessions, no saved cookies).

Per-agent opt-out via `!browser-automation` is already supported
(PR #71 UNION merge semantics) if any specific role shouldn't have it.

Closes #213

org-templates/reno-stars/org.yaml

@@ -7,6 +7,8 @@ defaults:
   runtime: claude-code
   tier: 3
   model: opus
+  plugins:
+    - browser-automation
   initial_prompt: |
     You just started. Set up silently — do NOT contact other agents yet.
     1. Read your system prompt at /configs/system-prompt.md — this defines YOUR role