docs: update project docs, NC Talk guide, Tina persona, and gitignore

- CLAUDE.md: add new auth/onboarding files to directory map, update
  security section (JWT/bcrypt/invite details), expand recently completed
- README.md: fix Web UI auth description, add User Management section
- TODO__Agents.md: mark NC Talk docs and auth/onboarding complete,
  update Holly onboarding plan to reflect single-instance multi-user approach
- docs/NEXTCLOUD_TALK_BOT.md: complete guide — occ commands, nginx config,
  clarify incoming vs outgoing HMAC difference, multi-user note, full
  troubleshooting table
- home/holly/persona/tina/: flesh out all four persona files with real
  content (DCC name origin, metal music, reading, foster cats, Holly's profile)
- .gitignore: exclude home/**/auth.json, invite.json, profile.json

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

.gitignore

@@ -9,6 +9,11 @@ __pycache__/
 # Session data (runtime state, not source)
 cortex/data/
 
+# User credentials and tokens — never commit
+home/**/auth.json
+home/**/invite.json
+home/**/profile.json
+
 # Syncthing Metadata
 .stfolder/