feat(fusion_portal): Phase 1b - Assessment Visit model + accessibility funding grouping

Adds fusion.assessment.visit: the hub that bundles a home visit's assessments and,
on completion, groups its ACCESSIBILITY assessments by funding workflow
(x_fc_sale_type) and creates ONE draft sale order per workflow, reusing the existing
MOD/ODSP/etc. pipelines + the chatter-note pattern. ADP assessments keep one-SO-each
for now (ADP multi-device grouping is Phase 2).

- New model + sequence (VISIT/YYYY/NNNN) + ACL + backend list/form/menu.
- visit_id added to fusion.assessment, fusion.accessibility.assessment, sale.order.
- action_complete_visit() group-and-routes; MOD $15k cap + income-threshold flag
  surfaced (informational, no auto-enforcement).

NOT YET: completion-email consolidation; ADP multi-device (Phase 2); portal
add-as-you-go workspace (Phase 3). Untested locally (Enterprise knowledge dep) -
to be verified on a westin-v19 clone before prod.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

fusion_portal/data/visit_data.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<odoo>
+    <data noupdate="1">
+        <!-- Reference sequence for assessment visits (VISIT/2026/0001) -->
+        <record id="seq_fusion_assessment_visit" model="ir.sequence">
+            <field name="name">Assessment Visit</field>
+            <field name="code">fusion.assessment.visit</field>
+            <field name="prefix">VISIT/%(year)s/</field>
+            <field name="padding">4</field>
+            <field name="company_id" eval="False"/>
+        </record>
+    </data>
+</odoo>