feat(nexa_coa_setup): analytic plans + seed accounts

- 'Customer Project' plan (renamed from 'Project' to avoid duplicate with
  project module's auto-created plan) — mandatory
- 'Department' plan (mandatory) — seeded with DEPT-DEV, DEPT-SALES,
  DEPT-ADMIN, DEPT-HOSTING
- 'SR&ED Tag' plan (optional) — seeded with 7 tag values:
  SRED-T4-DEV-SALARY, SRED-SPECIFIED-EMPLOYEE,
  SRED-CONTRACTOR-CA-ARM-LENGTH, SRED-CONTRACTOR-CA-NON-ARM-LENGTH,
  SRED-MATERIALS-CONSUMED, SRED-OVERHEAD-PROXY-BASIS, NOT-ELIGIBLE

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

nexa_coa_setup/data/05_account_analytic_plan.xml

@@ -1,5 +1,24 @@
 <?xml version="1.0" encoding="utf-8"?>
 <odoo>
     <data noupdate="0">
+
+        <!-- Named 'Customer Project' to avoid collision with the project module's
+             auto-created 'Project' plan. This is where customer-engagement
+             analytic accounts (PRJ-YYYY-CUST-NAME) live. -->
+        <record id="plan_project" model="account.analytic.plan">
+            <field name="name">Customer Project</field>
+            <field name="default_applicability">mandatory</field>
+        </record>
+
+        <record id="plan_department" model="account.analytic.plan">
+            <field name="name">Department</field>
+            <field name="default_applicability">mandatory</field>
+        </record>
+
+        <record id="plan_sred_tag" model="account.analytic.plan">
+            <field name="name">SR&amp;ED Tag</field>
+            <field name="default_applicability">optional</field>
+        </record>
+
     </data>
 </odoo>