feat: 영수증 스캔 네이티브 카메라(@capacitor/camera)

- 앱에서 촬영/갤러리 선택 프롬프트로 영수증 입력 (웹은 파일선택 폴백)
- AndroidManifest CAMERA 권한 추가

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

package-lock.json

@@ -10,6 +10,7 @@
       "dependencies": {
         "@capacitor/android": "^8.3.4",
         "@capacitor/app": "^8.1.0",
+        "@capacitor/camera": "^8.2.0",
         "@capacitor/cli": "^8.3.4",
         "@capacitor/core": "^8.3.4",
         "@capacitor/preferences": "^8.0.1",
@@ -542,6 +543,15 @@
         "@capacitor/core": ">=8.0.0"
       }
     },
+    "node_modules/@capacitor/camera": {
+      "version": "8.2.0",
+      "resolved": "https://registry.npmjs.org/@capacitor/camera/-/camera-8.2.0.tgz",
+      "integrity": "sha512-hYfrT6xpL936qoEkIpJzSnb0fQCaTkOux1cXzGBfH8QLOGqr6gSLiWZlZz/fqMPmMKJMNRBqlTQkj5fuMhVZog==",
+      "license": "MIT",
+      "peerDependencies": {
+        "@capacitor/core": ">=8.0.0"
+      }
+    },
     "node_modules/@capacitor/cli": {
       "version": "8.3.4",
       "resolved": "https://registry.npmjs.org/@capacitor/cli/-/cli-8.3.4.tgz",