feat(fusion_plating_shopfloor): fpRpc wrapper + env_for_tablet_tech helper (P6.3.1)

Client-side fpRpc() is a drop-in for rpc() that automatically injects
tablet_tech_id from the tech_store into every action call. Read-only
endpoints can keep using plain rpc().

Server-side env_for_tablet_tech(env, tablet_tech_id) returns an env
scoped via with_user() when the id is a valid active user; otherwise
returns the original env unchanged. Controllers call this at the top
of action methods so all subsequent writes carry the right uid.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

fusion_plating/fusion_plating_shopfloor/controllers/_tablet_audit.py

@@ -0,0 +1,42 @@
+# -*- coding: utf-8 -*-
+# Copyright 2026 Nexa Systems Inc.
+# License OPL-1 (Odoo Proprietary License v1.0)
+"""Helper for audit-credit propagation (Phase 6.3 tablet redesign).
+
+Controllers that accept an optional `tablet_tech_id` kwarg use this
+helper to switch their `env` to the tech-of-record before performing
+writes. The result: chatter posts + create_uid/write_uid carry the
+unlocked tech's identity, not the tablet's persistent session user.
+"""
+import logging
+
+_logger = logging.getLogger(__name__)
+
+
+def env_for_tablet_tech(env, tablet_tech_id):
+    """Return an env scoped to `tablet_tech_id` if it's a valid user;
+    otherwise return the original env unchanged.
+
+    Validation: the user must exist and be active. We deliberately do
+    NOT cross-check that they actually unlocked recently — the OWL
+    component is the source of truth for "who's at the tablet right
+    now", and the only path that produces a tablet_tech_id is a
+    successful /fp/tablet/unlock followed by an active session in the
+    OWL tech_store.
+    """
+    if not tablet_tech_id:
+        return env
+    try:
+        tech_id = int(tablet_tech_id)
+    except (TypeError, ValueError):
+        return env
+    User = env['res.users'].sudo()
+    tech = User.browse(tech_id)
+    if not tech.exists() or not tech.active:
+        _logger.warning(
+            "tablet_tech_id %s invalid (not found or inactive); "
+            "falling back to session uid %s",
+            tablet_tech_id, env.uid,
+        )
+        return env
+    return env(user=tech_id)