Keep internal SOURCE notes out of the public deploy; noindex staging

SOURCE-ingamichaelsen.md (content capture + build TODOs) was being served
publicly — gitignore + untrack it (stays local). Add robots.txt Disallow for
the staging site; remove when the real domain goes live.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.gitignore

@@ -1,2 +1,3 @@
 # Local Claude Code settings (personal — not deployed)
 .claude/
+SOURCE-ingamichaelsen.md