chore(tauri): enable devtools in dev builds only

Removes the explicit "devtools": false from tauri.conf.json so the Tauri
default applies (true in debug, false in release). Auto-opens the inspector
in the setup hook under #[cfg(debug_assertions)] so contributors get DevTools
on `npm run tauri:dev` without right-clicking.

`cargo check --release` confirms the open_devtools() call is hard-stripped
from production binaries — the symbol does not exist in the release build.

Helps debug WebView-side issues (CORS, TLS, axios responses) that the
Rust-only logging mode does not capture.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src-tauri/tauri.conf.json

@@ -23,8 +23,7 @@
         "decorations": true,
         "transparent": false,
         "visible": true,
-        "dragDropEnabled": false,
-        "devtools": false
+        "dragDropEnabled": false
       }
     ],
     "security": {