mount: ownership options are checked state; drift remounts without a lazy detach (fixes #642)

[noahgift]

Fixes #642.

Defect: the mount check compared only the findmnt SOURCE. A share mounted from the right source with the wrong uid/gid/file_mode/dir_mode/mode reported converged, and apply never remounted it. This is a tool reporting what it did not measure. Found on lambda-labs: the NAS gid must change so the course user can write the share (paiml/infra#1208), and 1.32.0 would have reported converged with the old gid still live.

Fix (src/resources/mount.rs):

• The check reads each declared ownership key back from findmnt -o OPTIONS.
  • Modes compare as numbers, so 0755 equals 755.
  • A user or group NAME resolves to its id with id -u or getent group.
  • A key the kernel omits (e.g. tmpfs uid=0) counts as the default.
• On drift, apply remounts with a plain umount and no umount -l fallback. A busy mount fails loudly and names the path, instead of being detached under live jobs.

Tests (src/resources/tests_mount_options.rs): the generated scripts run against a fake findmnt/umount/mount, so the tests measure what the host is told, not the script text. There are 8 tests; all 41 resources::tests_mount* pass and clippy -D warnings is clean.

Discriminates: with options_condition neutralised, 5 of the 8 go RED: the wrong gid, the wrong mode, the group name, the remount on drift, and the refusal when busy. The 3 converged cases stay green, as they must.

🤖 Generated with Claude Code

[noahgift]

quorum-review (AD-04): NOT agreed (auto_merge: checked=true was_armed=false disarmed=false)

{
 "ticket": "PMAT-642",
 "head": "6c1cabf22bf4f324990b6258b4166bfc30f06be9",
 "width": 3,
 "executor": "agy",
 "agreed": false,
 "auto_merge": {
  "checked": true,
  "was_armed": false,
  "disarmed": false,
  "note": "auto-merge not armed"
 },
 "lanes": [
  {
   "lane": 1,
   "verdict": "FAIL",
   "findings": 1
  },
  {
   "lane": 2,
   "verdict": "FAIL",
   "findings": 1
  },
  {
   "lane": 3,
   "verdict": "PASS",
   "findings": 0
  }
 ]
}

[noahgift]

quorum-review (AD-04): three PASS — agreed (auto_merge: checked=true was_armed=false disarmed=false)

{
 "ticket": "PMAT-642",
 "head": "0b5882e06de1bdf2197de0b09ad7ac953cc465cf",
 "width": 3,
 "executor": "agy",
 "agreed": true,
 "auto_merge": {
  "checked": true,
  "was_armed": false,
  "disarmed": false,
  "note": "auto-merge not armed"
 },
 "lanes": [
  {
   "lane": 1,
   "verdict": "PASS",
   "findings": 4
  },
  {
   "lane": 2,
   "verdict": "PASS",
   "findings": 0
  },
  {
   "lane": 3,
   "verdict": "PASS",
   "findings": 0
  }
 ]
}

[noahgift]

Quorum 3/3 PASS at 0b5882e (R1 refuted the omitted-key wildcard, fixed and re-reviewed). After review, 184876b adds only tests/falsification_642_mount_ownership_is_state.rs, an integration target so the gate can run cargo test --test. It reuses the reviewed lib cases, and with mount.rs at base, 4 of 5 are red. 3a487e2 is the receipt; scripts/quorum-gate.sh passes.