feat(fusion_helpdesk): Critical flag, KPI cards, colored stage pills

Three coordinated changes on top of the section grouping:

1. **Mark as Critical** — a red chip on the New tab sets priority='3'
   when submitted. The central post-create hook auto-applies a "Critical"
   helpdesk.tag (shipped via fusion_helpdesk_central data XML, noupdate=1
   so support can recolor without losing it on upgrade), giving support
   a kanban-groupable signal that doesn't rely on remembering what
   priority='3' means. Scoped to in-app-channel tickets only, so a
   support agent manually setting Urgent on their own ticket isn't
   silently tagged.

2. **KPI cards above the sections** — Total / Open / Closed / Critical
   in a 4-up grid (auto-collapses to 2x2 under 540px). Each card uses
   its own saturated gradient so it reads on both light and dark mode —
   the dialog backdrop is irrelevant because the gradient brings its
   own background. Counts are computed in JS from state.tickets so they
   always match what's rendered below.

3. **Colored stage pills** — red Critical, green Solved, dark-yellow New,
   orange Cancelled, blue for In Progress / Testing / On Hold. Critical
   priority gets a *separate* red pill alongside the stage pill so you
   keep stage info even on escalated tickets. Stage matching is
   substring-based (lowercased) so a renamed "Resolved" or "Done" stage
   on central still maps to the green pill.

Tests cover the new is_critical=True → priority='3' wiring and the
default omission so SLA / stage defaults keep working for normal
tickets. Bumps fusion_helpdesk to 19.0.1.7.0 and
fusion_helpdesk_central to 19.0.1.2.0. End-to-end smoke test verified
live: priority=3 + x_fc_client_label triggers the Critical tag.

fusion_helpdesk/utils.py

@@ -49,13 +49,19 @@ def _norm_email(*candidates):
 
 
 def build_ticket_vals(kind, subject, body_html, team_id, client_label,
-                      reporter_name, reporter_email, company_name):
+                      reporter_name, reporter_email, company_name,
+                      is_critical=False):
     """Construct the `helpdesk.ticket` create vals for a forwarded report.
 
     The identity fields (`partner_email`, `partner_name`,
     `partner_company_name`) drive native helpdesk find-or-create of the
     customer partner + follower subscription on the central Odoo, and
     `x_fc_client_label` tags the deployment for the scoped inbox.
+
+    When `is_critical` is set, we pass `priority='3'` (Urgent) — the central
+    post-create hook then auto-applies the Critical helpdesk.tag so support
+    can filter by it. Priority drives the inbox's Critical section too
+    (see `bucket_ticket`), so the same toggle is load-bearing on both ends.
     """
     kind_label = 'Bug Report' if kind == 'bug' else 'Feature Request'
     prefix = ('[%s] ' % client_label) if client_label else ''
@@ -72,6 +78,8 @@ def build_ticket_vals(kind, subject, body_html, team_id, client_label,
         vals['partner_company_name'] = company_name
     if client_label:
         vals['x_fc_client_label'] = client_label
+    if is_critical:
+        vals['priority'] = '3'
     return vals