[dashboards] Fix MCP proxy auth + setup docs

[matthallett1]

Summary

• Fix proxy auth method — The MCP proxy was sending the access key as Authorization: Bearer header, but open-brain-mcp expects ?key= query parameter. Search and capture silently failed through the dashboard.
• Improve setup docs — Rewrote Quick Start with a credential source table, OAuth sign-in gotcha, and search troubleshooting (OpenRouter key, embeddings, similarity threshold).
• Harden gitignore — Added .env.local, .env.*.local, and deno.lock to prevent credential/artifact leaks.

Found during live testing

Issue	Root cause	Fix
Search always returned "No thoughts found"	Proxy sent key as Bearer header instead of query param	Changed to ?key= in fetch URL
"Database error querying schema" on sign-in	OAuth user has no password	Documented: send recovery email or create email/password user
Search still empty after proxy fix	Stale OpenRouter API key in Supabase secrets	Updated secret (not in code) + documented in troubleshooting

Test plan

• Verified locally: stats load (2059 thoughts), search returns results, capture works
• Tested with real Supabase project + deployed Edge Function
• Verify CI passes (markdownlint, metadata check)

🤖 Generated with Claude Code

[github-actions]

OB1 Automated Review

✅ Folder structure — All files are in allowed directories
✅ Required files — README.md and metadata.json found in all contribution folders
✅ Metadata valid — All metadata.json files have required fields
✅ No credentials — No API keys, tokens, or secrets detected
✅ SQL safety — No destructive SQL or core table modifications
✅ Category artifacts — Required file types present for each category
✅ PR format — Title follows [category] Description format
✅ No binary blobs — No oversized or binary files
✅ README completeness — All READMEs include Prerequisites, Steps, and Expected Outcome
✅ Primitive dependencies — All declared primitive dependencies exist and are linked in README
✅ LLM clarity review — Covered by Claude PR Review workflow
✅ Remote MCP pattern — No local MCP server patterns detected — uses remote MCP correctly
❌ Scope check — Files changed outside contribution folder(s):

• .gitignore
  Contribution PRs should only modify files in their own folder.
  ✅ Internal links — All relative links in READMEs resolve to existing files

Result: 13/14 checks passed. Please fix the issues above and push again.

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Post-Merge Tasks

These don't block merge — they're reminders for admins after this PR lands.

• Add Open Brain Dashboard to dashboards/README.md
• Add Open Brain Dashboard to root README.md community contributions section
• Add Mads Bergdal (aka Headcrest) (@headcrest) to CONTRIBUTORS.md
• Post in OB1 Discord #show-and-tell

[justfinethanku]

Combined into PR #83 with the original dashboard from #57.

Matt — next time, submit this as a PR review on the original PR with requested changes, or push fixes directly to the contributor's branch. Opening a separate PR to patch an open PR creates a dependency chain that's a pain to merge. The fixes were good, the process just needs to be tighter.