refactor(jobs): address code review feedback on fp.job.step.timelog (Task 1.7)

- I1: Add supervisor ACL row on fp.job.step.timelog. The other
  job-related models all have a 3-tier (operator/supervisor/
  manager) pattern; timelog had been operator+manager only with
  no comment explaining why. Adding the supervisor row for
  consistency — supervisors can write timelogs the same as
  operators.
- I2: Capture fields.Datetime.now() once in button_start and
  reuse for both the step's first-start audit timestamp and the
  new timelog's date_started. Mirrors button_finish's pattern.
  Eliminates microsecond drift between two related timestamps.
- M6: Update stale comment in fp_job_step.py that said
  'duration_actual will be sum of timelog rows once Task 1.7
  lands' — Task 1.7 has landed; replace with current behaviour.

Manifest 19.0.8.6.0 → 19.0.8.6.1.

Part of: native job model migration (spec 2026-04-25)
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

fusion_plating/fusion_plating/__manifest__.py

@@ -5,7 +5,7 @@
 
 {
     'name': 'Fusion Plating',
-    'version': '19.0.8.6.0',
+    'version': '19.0.8.6.1',
     'category': 'Manufacturing/Plating',
     'summary': 'Core plating / metal finishing ERP: facilities, processes, tanks, baths, jobs, operators.',
     'description': """