feat(pwa-offline): Pinia store + IndexedDB; contexto para cache/eliminación; toasts; compatibilidad PWA offline

- Agrega @pinia/nuxt, idb y store central (stores/music.ts)
- Cacheo manual desde menú contextual y borrado (TrackContextMenu)
- Ícono verde para canciones cacheadas, sin auto-cache al reproducir
- Toasts de feedback (stores/toast.ts, ToastContainer)
- Fallback offline de listado a IndexedDB; fix MUSIC_DIR absoluto en preview/prod
- Ajustes PWA: navigateFallback '/', devOptions, workbox condicional
- Estilos y animación del context menu (tema light/dark, blur fuerte)
- Correcciones de sintaxis y posicionamiento exacto al cursor

package-lock.json

@@ -9,10 +9,13 @@
       "version": "1.0.0",
       "hasInstallScript": true,
       "dependencies": {
+        "@pinia/nuxt": "^0.11.2",
         "@vite-pwa/nuxt": "^1.0.4",
         "@vueuse/core": "^10.5.0",
         "@vueuse/nuxt": "^10.5.0",
-        "lucide-vue-next": "^0.536.0"
+        "idb": "^8.0.3",
+        "lucide-vue-next": "^0.536.0",
+        "pinia": "^3.0.3"
       },
       "devDependencies": {
         "@nuxt/devtools": "latest",
@@ -4202,6 +4205,21 @@
         "url": "https://opencollective.com/parcel"
       }
     },
+    "node_modules/@pinia/nuxt": {
+      "version": "0.11.2",
+      "resolved": "https://registry.npmjs.org/@pinia/nuxt/-/nuxt-0.11.2.tgz",
+      "integrity": "sha512-CgvSWpbktxxWBV7ModhAcsExsQZqpPq6vMYEe9DexmmY6959ev8ukL4iFhr/qov2Nb9cQAWd7niFDnaWkN+FHg==",
+      "license": "MIT",
+      "dependencies": {
+        "@nuxt/kit": "^3.9.0"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/posva"
+      },
+      "peerDependencies": {
+        "pinia": "^3.0.3"
+      }
+    },
     "node_modules/@pkgjs/parseargs": {
       "version": "0.11.0",
       "resolved": "https://registry.npmjs.org/@pkgjs/parseargs/-/parseargs-0.11.0.tgz",
@@ -8770,9 +8788,9 @@
       }
     },
     "node_modules/idb": {
-      "version": "7.1.1",
-      "resolved": "https://registry.npmjs.org/idb/-/idb-7.1.1.tgz",
-      "integrity": "sha512-gchesWBzyvGHRO9W8tzUWFDycow5gwjvFKfyV9FF32Y7F50yZMp7mP+T2mJIWFx49zicqyC4uefHM17o6xKIVQ==",
+      "version": "8.0.3",
+      "resolved": "https://registry.npmjs.org/idb/-/idb-8.0.3.tgz",
+      "integrity": "sha512-LtwtVyVYO5BqRvcsKuB2iUMnHwPVByPCXFXOpuU96IZPPoPN6xjOGxZQ74pgSVVLQWtUOYgyeL4GE98BY5D3wg==",
       "license": "ISC"
     },
     "node_modules/ieee754": {
@@ -11251,6 +11269,36 @@
         "url": "https://github.com/sponsors/jonschlinkert"
       }
     },
+    "node_modules/pinia": {
+      "version": "3.0.3",
+      "resolved": "https://registry.npmjs.org/pinia/-/pinia-3.0.3.tgz",
+      "integrity": "sha512-ttXO/InUULUXkMHpTdp9Fj4hLpD/2AoJdmAbAeW2yu1iy1k+pkFekQXw5VpC0/5p51IOR/jDaDRfRWRnMMsGOA==",
+      "license": "MIT",
+      "dependencies": {
+        "@vue/devtools-api": "^7.7.2"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/posva"
+      },
+      "peerDependencies": {
+        "typescript": ">=4.4.4",
+        "vue": "^2.7.0 || ^3.5.11"
+      },
+      "peerDependenciesMeta": {
+        "typescript": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/pinia/node_modules/@vue/devtools-api": {
+      "version": "7.7.7",
+      "resolved": "https://registry.npmjs.org/@vue/devtools-api/-/devtools-api-7.7.7.tgz",
+      "integrity": "sha512-lwOnNBH2e7x1fIIbVT7yF5D+YWhqELm55/4ZKf45R9T8r9dE2AIOy8HKjfqzGsoTHFbWbr337O4E0A0QADnjBg==",
+      "license": "MIT",
+      "dependencies": {
+        "@vue/devtools-kit": "^7.7.7"
+      }
+    },
     "node_modules/pkg-types": {
       "version": "2.2.0",
       "resolved": "https://registry.npmjs.org/pkg-types/-/pkg-types-2.2.0.tgz",
@@ -14752,6 +14800,12 @@
         "workbox-core": "7.3.0"
       }
     },
+    "node_modules/workbox-background-sync/node_modules/idb": {
+      "version": "7.1.1",
+      "resolved": "https://registry.npmjs.org/idb/-/idb-7.1.1.tgz",
+      "integrity": "sha512-gchesWBzyvGHRO9W8tzUWFDycow5gwjvFKfyV9FF32Y7F50yZMp7mP+T2mJIWFx49zicqyC4uefHM17o6xKIVQ==",
+      "license": "ISC"
+    },
     "node_modules/workbox-broadcast-update": {
       "version": "7.3.0",
       "resolved": "https://registry.npmjs.org/workbox-broadcast-update/-/workbox-broadcast-update-7.3.0.tgz",
@@ -15090,6 +15144,12 @@
         "workbox-core": "7.3.0"
       }
     },
+    "node_modules/workbox-expiration/node_modules/idb": {
+      "version": "7.1.1",
+      "resolved": "https://registry.npmjs.org/idb/-/idb-7.1.1.tgz",
+      "integrity": "sha512-gchesWBzyvGHRO9W8tzUWFDycow5gwjvFKfyV9FF32Y7F50yZMp7mP+T2mJIWFx49zicqyC4uefHM17o6xKIVQ==",
+      "license": "ISC"
+    },
     "node_modules/workbox-google-analytics": {
       "version": "7.3.0",
       "resolved": "https://registry.npmjs.org/workbox-google-analytics/-/workbox-google-analytics-7.3.0.tgz",