feat(fusion_helpdesk): owner-approval engagement flow + AI summary + reporting

Ships the design spec at docs/superpowers/specs/2026-05-27-owner-approval-flow-design.md.

What's new on central (fusion_helpdesk_central 19.0.1.2.0 -> 19.0.2.0.0):

- Engagement model: 8 new fields on helpdesk.ticket (state, snapshotted
  owner email/name, single-use UUID4 token, sent/reminded/decided
  timestamps, AI summary, stored-computed turnaround hours).
- Wizard: single + bulk modes on one fusion.helpdesk.engagement.wizard
  TransientModel with a child wizard.line for per-ticket bulk summaries.
  default_get pulls the OpenAI summary on open; AI fan-out for bulk is
  parallel via ThreadPoolExecutor (max 5 workers, 30s overall cap).
- OpenAI client in utils.py — stdlib urllib, 15s per-call timeout, every
  failure collapses to '' so the wizard's manual-summary fallback fires.
- Public portal: /fusion_helpdesk/engagement/<token>/<decision> GET +
  POST, four branded standalone QWeb pages (confirm/done/invalid/error).
  Token is single-use, cleared on confirm. Decision posts a public
  comment attributed to the resolved owner partner; chatter propagates
  to the employee's My Tickets thread per the "fully visible" UX choice.
- Mail templates (single + bulk) with magic-link buttons. Bulk template
  renders one card per ticket, each with its own approve/reject URL.
- Reminder cron: daily, single-shot per engagement, configurable via
  fusion_helpdesk_central.engagement_reminder_days ICP (default 3, 0
  disables).
- Reporting dashboard: pivot/graph/list/kanban over helpdesk.ticket
  filtered to engaged ones, with avg-turnaround measure. Menu lives
  under Helpdesk > Reporting > Owner Engagements.
- Client_key extended with owner_email/owner_name fields; ticket.create
  upserts them from the client-side piggyback (no new sync endpoint).
- 100% coverage on utils + integration tests on wizard, controllers,
  re-engagement, cron, computed turnaround. OpenAI mocked in CI.

What's new on client (fusion_helpdesk 19.0.1.7.1 -> 19.0.2.0.0):

- Two new ICP settings: fusion_helpdesk.owner_email / .owner_name with
  a new "Owner Approval" block in Settings > Fusion Helpdesk.
- controllers/main.py::submit piggybacks both keys on every ticket
  payload so central keeps client_key.owner_email/name fresh
  automatically.

Verified live end-to-end on entech -> nexa: payload upsert, wizard with
mocked AI, action_send, portal GET/POST/GET-again cycle, second click
hits the friendly invalid-token page. Token entropy = 122 bits (UUID4).

fusion_helpdesk_central/views/engagement_wizard_views.xml

@@ -0,0 +1,67 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+    Copyright 2026 Nexa Systems Inc.
+    License OPL-1
+
+    The owner-approval engagement wizard, opened from the ticket form
+    button OR the list-view bulk server action. Branches on `mode` to
+    show either the single-ticket layout (one AI summary field) or the
+    bulk layout (an editable line per ticket).
+-->
+<odoo>
+
+    <record id="view_engagement_wizard_form" model="ir.ui.view">
+        <field name="name">fusion.helpdesk.engagement.wizard.form</field>
+        <field name="model">fusion.helpdesk.engagement.wizard</field>
+        <field name="arch" type="xml">
+            <form string="Request Owner Approval">
+                <field name="mode" invisible="1"/>
+                <field name="ticket_id" invisible="1"/>
+
+                <group>
+                    <group>
+                        <field name="owner_name_display" string="Owner"/>
+                        <field name="owner_email_display" string="Owner Email" widget="email"/>
+                    </group>
+                </group>
+
+                <div class="alert alert-warning" role="alert"
+                     invisible="not ai_unavailable">
+                    <strong>AI summary unavailable.</strong>
+                    OpenAI didn't return a summary (no API key set, rate limit,
+                    or network error). Write a quick brief below before sending —
+                    everything else still works.
+                </div>
+
+                <!-- Single mode: one summary field for the one ticket. -->
+                <group invisible="mode != 'single'">
+                    <field name="personal_note"
+                           placeholder="One-line note that appears above the summary in the email…"/>
+                    <field name="ai_summary" string="Summary to send"
+                           placeholder="Bullet-point summary that the owner will read first." />
+                </group>
+
+                <!-- Bulk mode: per-ticket lines, each with its own summary. -->
+                <group invisible="mode != 'bulk'">
+                    <field name="personal_note"
+                           placeholder="One-line note that appears once at the top of the combined email…"/>
+                </group>
+                <field name="line_ids" invisible="mode != 'bulk'" nolabel="1">
+                    <list editable="bottom" create="0" delete="0">
+                        <field name="ticket_id" readonly="1"/>
+                        <field name="ticket_name" readonly="1"/>
+                        <field name="ai_summary"/>
+                    </list>
+                </field>
+
+                <footer>
+                    <button name="action_send" type="object"
+                            string="Send Engagement"
+                            class="btn-primary"/>
+                    <button special="cancel" string="Cancel"/>
+                </footer>
+            </form>
+        </field>
+    </record>
+
+</odoo>