feat(checkout): searchable address fields and Rajaongkir integration

Admin SPA:
- Changed billing/shipping state from Select to SearchableSelect

Customer SPA:
- Added cmdk package for command palette
- Created popover, command, and searchable-select UI components
- Added searchable country and state fields to checkout
- Fetches countries/states from /countries API
- Auto-clears state when country changes

Backend:
- Added generic woonoow/shipping/before_calculate hook
- Removed hardcoded Rajaongkir session handling

Documentation:
- Updated RAJAONGKIR_INTEGRATION.md with:
  - Complete searchable destination selector plugin code
  - JavaScript implementation
  - React component version
  - REST API endpoint for destination search

customer-spa/package-lock.json

@@ -25,6 +25,7 @@
                 "@tanstack/react-query": "^5.90.5",
                 "class-variance-authority": "^0.7.1",
                 "clsx": "^2.1.1",
+                "cmdk": "^1.1.1",
                 "lucide-react": "^0.547.0",
                 "react": "^18.3.1",
                 "react-dom": "^18.3.1",
@@ -3597,6 +3598,22 @@
                 "node": ">=6"
             }
         },
+        "node_modules/cmdk": {
+            "version": "1.1.1",
+            "resolved": "https://registry.npmjs.org/cmdk/-/cmdk-1.1.1.tgz",
+            "integrity": "sha512-Vsv7kFaXm+ptHDMZ7izaRsP70GgrW9NBNGswt9OZaVBLlE0SNpDq8eu/VGXyF9r7M0azK3Wy7OlYXsuyYLFzHg==",
+            "license": "MIT",
+            "dependencies": {
+                "@radix-ui/react-compose-refs": "^1.1.1",
+                "@radix-ui/react-dialog": "^1.1.6",
+                "@radix-ui/react-id": "^1.1.0",
+                "@radix-ui/react-primitive": "^2.0.2"
+            },
+            "peerDependencies": {
+                "react": "^18 || ^19 || ^19.0.0-rc",
+                "react-dom": "^18 || ^19 || ^19.0.0-rc"
+            }
+        },
         "node_modules/color-convert": {
             "version": "2.0.1",
             "resolved": "https://registry.npmjs.org/color-convert/-/color-convert-2.0.1.tgz",