fix(newos4): print the checkpoint name actually saved (auto)

Task 2 + ship of plan 2026-10-27_061724-newos4-checkpoint-name-mismatch.md.

module-system.js `checkpoint` read the clock a second time for the printed
name, so the name in "✅ Checkpoint created: <name>" differed from the name on
disk by >=1ms whenever no explicit name was given. It now prints the value
returned by fs.checkpoint(). try/catch and error strings unchanged.

Bundles rebuilt (rebuild-bundles.py); LATEST_VER in module-loader.js and all
three ?v= tags in main.html (core-bundle, module-loader, critical-ext-bundle)
bumped v4.6.101 -> v4.6.102.

Verification:
  $ node --check modules/core/module-system.js
  SYNTAX OK
  $ node --check modules/core/core-bundle.js
  BUNDLE SYNTAX OK
  $ node modules/test/test-vfs-checkpoint.js   (x5)
  test-vfs-checkpoint: 10 passed, 0 failed
  $ curl -s https://webx11.duckdns.org/spaces/newos4/main.html | grep -o 'core-bundle.js?v=[^"]*'
  core-bundle.js?v=v4.6.102
  $ python3 scripts/newos4-maintain.py
  PASS: version v4.6.102 x3 in main.html (expect 3) ... maintenance result: OK
  $ python3 scripts/newos4-skill-audit.py
  skill audit: 7/7 pass

0 files changed, 0 insertions, 0 deletions