Main: 3b95e7831b11b17627dff16843bc087bfca397ec; Linux; process umask 0002.
Started: vp run dev in /home/ubuntu/wt/issue-14967; isolated .t3 state.
Browser: T3 collaborative Browser, Chromium, 1280x800.
Attempt 1: General -> environment fs-07 -> Confirm thread archiving: database-backed setting; settings.json unchanged at 0600. Not the affected writer.
Attempt 2: chmod 600 .t3/userdata/settings.json; Settings -> Providers -> Enable Claude switch off.
Before: 600 .t3/userdata/settings.json
After: 664 .t3/userdata/settings.json
Saved contents include providerInstances.claudeAgent.enabled=false.
Crash/power-loss outcome not simulated; no claim of observed empty/stale files.
Duplicate scan: 880 open issues, created within 90 days; atomic/durability/file mode/permission bits/fsync/0644/0600 title matches found only this issue and different symptoms #15143 and #4750.