Real app filesystem observations
Linux; Chromium 156; 1280x800; light theme; umask 0002; fresh synthetic state.
AI-assisted; verified with the tests and tools listed above.
Paths and process IDs normalized; syscall results unchanged.

BASE 24e77473ecf41bc1f7142529c7911c1c1aae1d76
stat userdata/settings.json: 0664
JSON providerInstances.claudeAgent.enabled: false
stat newly server-created userdata/keybindings.json: 0664
Ordered strace excerpt for final settings save:
worker rename("T3_HOME/userdata/settings.json.pKUHFh/contents.tmp", "T3_HOME/userdata/settings.json") = 0
Full trace contains no fsync/fdatasync of any settings temporary file and no parent-directory sync after these settings renames.

New keybindings file creation excerpt:
worker rename("T3_HOME/userdata/keybindings.json.IdmeyJ/contents.tmp", "T3_HOME/userdata/keybindings.json") = 0

HEAD d5345dea3346274bd52dd3474f276ba69079614b
stat userdata/settings.json: 0600
JSON providerInstances.claudeAgent.enabled: false
stat newly server-created userdata/keybindings.json: 0600
Ordered strace excerpt for final settings save:
worker chmod("T3_HOME/userdata/settings.json.myhW57/contents.tmp", 0600) = 0
worker fsync(48<T3_HOME/userdata/settings.json.myhW57/contents.tmp>) = 0
worker rename("T3_HOME/userdata/settings.json.myhW57/contents.tmp", "T3_HOME/userdata/settings.json") = 0
worker fsync(48<T3_HOME/userdata>) = 0

New keybindings file creation excerpt:
worker chmod("T3_HOME/userdata/keybindings.json.gKqxOA/contents.tmp", 0600) = 0
worker fsync(60<T3_HOME/userdata/keybindings.json.gKqxOA/contents.tmp>) = 0
worker rename("T3_HOME/userdata/keybindings.json.gKqxOA/contents.tmp", "T3_HOME/userdata/keybindings.json") = 0