feat(nexa_coa_setup): module skeleton with hooks stub

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

nexa_coa_setup/README.md

@@ -0,0 +1,26 @@
+# Nexa Systems — Chart of Accounts Setup
+
+Custom Odoo 19 module that configures the chart of accounts, taxes,
+fiscal positions, analytic plans, and partner records for Nexa Systems Inc.
+
+## Install
+
+```
+docker exec odoo-nexa-app odoo -c /etc/odoo/odoo.conf -d nexamain \
+  -i nexa_coa_setup --no-http --stop-after-init
+```
+
+## Update
+
+```
+docker exec odoo-nexa-app odoo -c /etc/odoo/odoo.conf -d nexamain \
+  -u nexa_coa_setup --no-http --stop-after-init
+```
+
+## Design reference
+
+See `docs/superpowers/specs/2026-05-12-nexa-coa-design.md`.
+
+## Safety
+
+Always take a pg_dump BEFORE running `-i` or `-u`. See `docs/superpowers/plans/2026-05-12-nexa-coa-setup.md` Phase 0.