refactor: organize features and standardize frontend tooling

Colocate feature views, components, stores, and upload logic; centralize shared map utilities without changing API behavior.

Add ESLint, Prettier, EditorConfig, and VS Code settings; standardize four-space indentation and document the project structure and checks.

Validation: npm run check, npm run build, and git diff --check.

tsconfig.app.json

@@ -1,16 +1,16 @@
 {
-  "extends": "@vue/tsconfig/tsconfig.dom.json",
-  "compilerOptions": {
-    "tsBuildInfoFile": "./node_modules/.tmp/tsconfig.app.tsbuildinfo",
-    "types": ["vite/client"],
-    "paths": {
-      "@/*": ["./src/*"]
-    },
+    "extends": "@vue/tsconfig/tsconfig.dom.json",
+    "compilerOptions": {
+        "tsBuildInfoFile": "./node_modules/.tmp/tsconfig.app.tsbuildinfo",
+        "types": ["vite/client"],
+        "paths": {
+            "@/*": ["./src/*"]
+        },
 
-    "noUnusedLocals": true,
-    "noUnusedParameters": true,
-    "erasableSyntaxOnly": true,
-    "noFallthroughCasesInSwitch": true
-  },
-  "include": ["src/**/*.ts", "src/**/*.tsx", "src/**/*.vue"]
+        "noUnusedLocals": true,
+        "noUnusedParameters": true,
+        "erasableSyntaxOnly": true,
+        "noFallthroughCasesInSwitch": true
+    },
+    "include": ["src/**/*.ts", "src/**/*.tsx", "src/**/*.vue"]
 }