0dfb4234 made every mode-less atomic write follow the process umask for NEW
targets, restoring what open("w")-based writers did. Ten of the folded sites
were not open("w") writers: they created the file through mkstemp and never
chmod'd, so on main a fresh file was 0600 regardless of umask (bot mailboxes,
relay inbox, turn markers, sessions.json, cron jobs/output, banner snapshot,
plugin toolset cache, presets, shell hooks, install id). CI caught the loosening
in tests/tools/test_bot_live_owner_delivery.py (st_mode 0o077 bits set).
Pass mode=0o600 explicitly at those ten sites; the umask default stays for the
sites that were open("w") on main. Invariant test exercises two real writers.
Each copy re-implemented temp+replace by hand and lacked one or more of
fsync, symlink preservation, atomic_replace's Windows-contention retry and
EXDEV/bind-mount fallback, mode preservation, or interrupt-safe temp
cleanup. Three (gateway/session_persistence, cron/suggestions,
agent/shell_hooks) were verbatim inlines of utils._atomic_write; two
modules defined their own directory-fsync helper, now utils.fsync_directory.
plugins/google_meet/_jsonfile.write_json_atomic is deleted (callers use the
canonical helper directly).
Behavior change: every one of these writers now fsyncs the payload, keeps a
pre-existing target's mode, cleans its temp file on BaseException, and
survives Windows AV/indexer contention and cross-device renames the way
config writes already did. cron/suggestions.json is 0600 from creation
(previously chmod'ed after the replace). Skipped on purpose: cron/jobs.py
two-phase staging, gateway/status._write_json_excl (create-only lock),
kanban_transfer staging (not atomic writers); tools/skill_usage.
_write_suppressed_names lives inside a PLUGIN-COMPAT block.
teknium1