Bump to v0.6.1 — native file upload, mention names, connection stability

- Native file picker (+) in compose box uploads via Rust backend (reqwest)
- Pasting a local file path auto-uploads instead of inserting text
- @mentions resolve to profile display names via useProfile hook
- Connection indicator uses 15s grace period before showing offline
- Upload uses correct nostr.build v2 API; Rust-side multipart for native picks
- Content parser extracted to src/lib/parsing.ts

src-tauri/capabilities/default.json

@@ -13,6 +13,13 @@
       "allow": [
         { "url": "https://nostr.build/**" }
       ]
+    },
+    "dialog:default",
+    {
+      "identifier": "fs:allow-read-file",
+      "allow": [
+        { "path": "**" }
+      ]
     }
   ]
 }