[fix] Release response lock reliably when browser/tab is closed

• Use pagehide (with sendBeacon / fetch keepalive) instead of deprecated unload
• Register current pageId in surveySession before render, so close request match
• Keep lock for page restored from back-forward cache (new direct function keep)
• Release lock when response is saved (saveall / savesubmit)
• close direct request never delete lock of another browser
• Fix multi access check when reloaded srid is a string
• Fix surveySession delay : global max time and disabled delay

Co-Authored-By: Claude Opus 5.5 noreply@anthropic.com

Summary by CodeRabbit

• Bug Fixes
  • Response locks now follow the active page during multi-access sessions and are released when navigating away. Returning to a suspended page attempts to reclaim its lock; if it is unavailable, the survey redirects.
  • Session cleanup now uses the configured global session limit. Nonpositive per-survey delays are treated as disabled.
  • Session locks are released only by the owning browser session or matching page, helping prevent one page from clearing another page’s lock.