Add profile relationship update chance

[RANGROO]

Summary

• add profile-owned RELATIONSHIP_UPDATE_CHANCE with a 50% default and 0-100 server-side bounds
• gate only automatic relationship LLM evaluations while preserving inline relationship command handling
• expose the setting in Stobe Profiles and seed fresh/default profile metadata

Validation

• PHP lint: changed PHP files (source and deployed runtime)
• STOBE_DB_NAME=stobe_test php tests/relationship_system_regression.php
• exact source/runtime SHA-256 match for all deployed files
• local ui/profiles.php HTTP 200 with the new setting and clarified help present
• browser: value 50, 0-100 bounds, paired slider/number controls, Copy to all key wiring, 390x844 layout, and no console errors
• delegated Claude Opus 5 review completed; only the setting help text needed clarification

Local deployment

Deployed branch head dfe4323 source files to /var/www/html/StobeServer in WSL distro DwemerAI4Skyrim3. Existing runtime configuration, database, logs, uploads, and plugin data were preserved.