feat(jobs): add fp.job.step.timelog for granular timer tracking

Each button_start opens a fresh timelog row; button_finish closes
the open row and recomputes step.duration_actual as the sum of all
interval durations. Replicates Odoo MRP's mrp.workorder.time_ids
granularity natively (no mrp dep).

Schema: step_id (M2O cascade), user_id, date_started,
date_finished, duration_minutes (computed, stored).

ACLs: operator get create permission on timelogs because
button_start creates them.

Tests: test_start_creates_timelog (asserts the log row exists,
date_finished is False, user_id is the current user) and
test_finish_closes_timelog (asserts log gets date_finished, has a
non-negative duration, and step.duration_actual matches).

Manifest 19.0.8.5.1 -> 19.0.8.6.0.

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/models/fp_job_step_timelog.py

@@ -0,0 +1,42 @@
+# -*- coding: utf-8 -*-
+# Copyright 2026 Nexa Systems Inc.
+# License OPL-1 (Odoo Proprietary License v1.0)
+#
+# fp.job.step.timelog — granular start/stop intervals for a step.
+#
+# Each step.button_start() opens a fresh timelog row. Each
+# step.button_finish() (or button_pause once added) closes the open
+# row. duration_actual on fp.job.step is the sum of these intervals.
+#
+# Replicates Odoo MRP's mrp.workorder.time_ids granularity natively
+# (without depending on the mrp module).
+
+from odoo import api, fields, models
+
+
+class FpJobStepTimeLog(models.Model):
+    _name = 'fp.job.step.timelog'
+    _description = 'Plating Job Step Time Log'
+    _order = 'date_started desc'
+
+    step_id = fields.Many2one(
+        'fp.job.step',
+        required=True,
+        ondelete='cascade',
+        index=True,
+    )
+    user_id = fields.Many2one('res.users', required=True)
+    date_started = fields.Datetime(required=True)
+    date_finished = fields.Datetime()
+    duration_minutes = fields.Float(
+        compute='_compute_duration', store=True,
+    )
+
+    @api.depends('date_started', 'date_finished')
+    def _compute_duration(self):
+        for log in self:
+            if log.date_started and log.date_finished:
+                delta = log.date_finished - log.date_started
+                log.duration_minutes = delta.total_seconds() / 60.0
+            else:
+                log.duration_minutes = 0.0