refactor: rename Wizamart to Orion across entire codebase

Replace all ~1,086 occurrences of Wizamart/wizamart/WIZAMART/WizaMart
with Orion/orion/ORION across 184 files. This includes database
identifiers, email addresses, domain references, R2 bucket names,
DNS prefixes, encryption salt, Celery app name, config defaults,
Docker configs, CI configs, documentation, seed data, and templates.

Renames homepage-wizamart.html template to homepage-orion.html.
Fixes duplicate file_pattern key in api.yaml architecture rule.

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

docs/architecture/language-i18n.md

@@ -1,6 +1,6 @@
 # Language & Internationalization (i18n) Architecture
 
-This document defines **strict rules** for implementing language support across the Wizamart platform.
+This document defines **strict rules** for implementing language support across the Orion platform.
 
 > **IMPORTANT:** These rules are mandatory. Violations will cause runtime errors, inconsistent UX, or security issues.
 
@@ -49,7 +49,7 @@ language = "lux"      # ❌ Use "lb"
 Language is resolved in this order (highest to lowest priority):
 
 1. **URL parameter** (`?lang=fr`)
-2. **Cookie** (`wizamart_language`)
+2. **Cookie** (`orion_language`)
 3. **User preference** (database: `preferred_language`)
 4. **Store default** (database: `storefront_language` or `dashboard_language`)
 5. **Accept-Language header** (browser)
@@ -270,7 +270,7 @@ async def set_language(request: LanguageSetRequest, response: Response):
         raise HTTPException(status_code=400, detail="Unsupported language")
 
     response.set_cookie(
-        key="wizamart_language",
+        key="orion_language",
         value=request.language,
         max_age=365 * 24 * 60 * 60,  # 1 year
         httponly=True,