Refresh login screen with server list UI and refactor platform config

Redesign login view with server card list, add/edit/delete modals,
and per-server ping status display. Rename ProxyOverrides to ClientConfig,
remove ConfigSystemInterface in favor of direct platform methods
(load_config, load_username, set_default_username, load_server_url),
remove SharedState threading in favor of global STATE, simplify
network_loop and audio setup, update proxy endpoint from /overrides
to /config, and clean up desktop launch configuration.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.gitea/workflows/build-release.yaml

@@ -42,47 +42,6 @@ jobs:
           path: target/release/mumble-web2-proxy
           retention-days: 5
 
-  macos_build:
-    runs-on: macos
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v5
-
-      - name: Restore Rust cache
-        uses: actions/cache/restore@v4
-        with:
-          path: |
-            ~/.cargo
-            ./target
-          key: rust-${{ runner.os }}-${{ hashFiles('**/Cargo.lock') }}
-          restore-keys: |
-            rust-${{ runner.os }}-
-
-      - name: Install cargo binstall
-        run: curl -L --proto '=https' --tlsv1.2 -sSf https://raw.githubusercontent.com/cargo-bins/cargo-binstall/main/install-from-binstall-release.sh | bash
-
-      - name: Install dioxus-cli
-        run: cargo binstall dioxus-cli --version 0.7.3 --no-confirm
-
-      - name: Build dioxus project
-        run: dx bundle --platform macos --release -p mumble-web2-gui
-
-      - name: Save Rust cache
-        if: always()
-        uses: actions/cache/save@v4
-        with:
-          path: |
-            ~/.cargo
-            ./target
-          key: rust-${{ runner.os }}-${{ hashFiles('**/Cargo.lock') }}
-
-      - name: Upload mumble-web2-gui Artifact
-        uses: https://gitea.com/actions/gitea-upload-artifact@v4
-        with:
-          name: mumble-web2-gui-macos-arm64
-          path: gui/dist
-          retention-days: 5
-
   windows_build:
     runs-on: windows
     steps: