feat(storefront): homepage, module gating, widget protocol, i18n fixes

Storefront homepage & module gating:
- CMS owns storefront GET / (slug="home" with 3-tier resolution)
- Catalog loses GET / (keeps /products only)
- Store root redirect (GET / → /store/dashboard or /store/login)
- Route gating: non-core modules return 404 when disabled for platform
- Seed store default homepages per platform

Widget protocol for customer dashboard:
- StorefrontDashboardCard contract in widgets.py
- Widget aggregator get_storefront_dashboard_cards()
- Orders and Loyalty module widget providers
- Dashboard template renders contributed cards (no module names)

Landing template module-agnostic:
- CTAs driven by storefront_nav (not hardcoded module names)
- Header actions check nav item IDs (not enabled_modules)
- Remove hardcoded "Add Product" sidebar button
- Remove all enabled_modules checks from storefront templates

i18n fixes:
- Title placeholder resolution ({{store_name}}) for store default pages
- Storefront nav label_keys prefixed with module code
- Add storefront.account.* keys to 6 modules (en/fr/de/lb)
- Header/footer CMS pages use get_translated_title(current_language)
- Footer labels use i18n keys instead of hardcoded English

Icon cleanup:
- Standardize on map-pin (remove location-marker alias)
- Replace all location-marker references across templates and docs

Docs:
- Storefront builder vision proposal (6 phases)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/modules/prospecting/templates/prospecting/admin/capture.html

@@ -105,7 +105,7 @@
             <button type="button" @click="getLocation()"
                     :disabled="gettingLocation"
                     class="inline-flex items-center justify-center px-4 py-2 text-sm font-medium leading-5 text-gray-700 dark:text-gray-300 transition-colors duration-150 bg-white dark:bg-gray-800 border border-gray-300 dark:border-gray-600 rounded-lg hover:bg-gray-50 dark:hover:bg-gray-700 focus:outline-none focus:shadow-outline-gray disabled:opacity-50">
-                <span x-html="$icon('location-marker', 'w-4 h-4 mr-2')"></span>
+                <span x-html="$icon('map-pin', 'w-4 h-4 mr-2')"></span>
                 <span x-text="gettingLocation ? 'Getting location...' : (form.location_lat ? 'Location saved' : 'Get Location')"></span>
             </button>
             <span x-show="form.location_lat" class="text-xs text-green-600 dark:text-green-400 self-center">