fix(fusion_helpdesk_central): findings + summary actually span full width

Previous fix (col=1 on the group) didn't work — Odoo still rendered
the group's string as a left-column label inside the form sheet's
flow, so the textarea got pushed into a narrow right column. The
summary field looked entirely missing because its content split
between the button row (on the right) and the textarea (collapsed
nowhere visible).

Right idiom (lifted from Odoo's own mail.compose.message wizard):
WIDE textareas live directly at the form level, not inside <group>.
Section titles use <separator string="…"> which renders as a
horizontal divider with the label above. The textarea then takes
the full sheet width naturally.

Same pattern applied to bulk mode for consistency.

Also moved Personal Note into the top compact group with Owner /
Owner Email since it's a one-line input that belongs with the
header info, not pretending to be a wide section.

Bumps fusion_helpdesk_central to 19.0.2.3.2.

fusion_helpdesk_central/__manifest__.py

@@ -3,7 +3,7 @@
 # License OPL-1
 {
     'name': 'Fusion Helpdesk Central — Client API Keys',
-    'version': '19.0.2.3.1',
+    'version': '19.0.2.3.2',
     'category': 'Productivity',
     'summary': 'Admin UI on the central Odoo for issuing per-client API '
                'keys used by fusion_helpdesk client deployments.',