[ADD] Claude Code ecosystem adapted from Copilot config

Port .github Copilot setup to Claude Code:
- CLAUDE.md: condensed project instructions (auto-loaded each session)
- .claude/skills: per-language guides (odoo-python, odoo-xml-views,
  odoo-qweb-html, odoo-javascript) + openspec-* workflow skills
- .claude/commands/opsx: /opsx:explore|propose|apply|archive slash commands

Original .github/ files kept untouched as extended reference.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.claude/skills/odoo-qweb-html/SKILL.md

@@ -0,0 +1,35 @@
+---
+name: odoo-qweb-html
+description: HTML/CSS/QWeb conventions for this repo (web templates, moving logic to the controller, styling). Use when editing QWeb templates, web views, or CSS in Odoo addons (website_sale_aplicoop).
+metadata:
+  type: reference
+---
+
+# HTML & CSS (Odoo/QWeb)
+
+## Golden rule
+**QWeb has strict limitations with complex logic.** Prepare ALL data in the Python controller
+and use only simple attribute access in the template. This avoids errors like
+`TypeError: 'NoneType' object is not callable`.
+
+```python
+# ❌ BAD — QWeb does not reliably parse this
+# <t t-set="price" t-value="info.get('price') or product.list_price or 0"/>
+
+# ✅ GOOD — pre-process in the controller
+def _prepare_product_display_info(self, product, price_info):
+    price = price_info.get(product.id, {}).get('price') or product.list_price or 0.0
+    return {'display_price': float(price), 'safe_uom': product.uom_id.category_id.name or ''}
+```
+```xml
+<!-- In template: simple access, no conditionals -->
+<span t-esc="product_display['display_price']"/>
+```
+
+## Style and conventions
+- Valid HTML5. 4-space indentation.
+- CSS: BEM or utility classes / Bootstrap when available. **No inline styles** except in well-justified cases.
+- Templates in `views/*.xml` or `static/src/xml/`. Styles in `static/src/css/` (load in manifest if needed).
+
+## Reference
+- `docs/QWEB_BEST_PRACTICES.md` for full logic/template separation patterns.