feat(ui): use Geist Sans font

Add @fontsource/geist-sans package and set it as the primary font
with system-ui and sans-serif as fallbacks.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

package.json

@@ -26,6 +26,7 @@
     "@agentclientprotocol/sdk": "^0.13.0",
     "@electron-toolkit/preload": "^3.0.2",
     "@electron-toolkit/utils": "^4.0.0",
+    "@fontsource/geist-sans": "^5.2.5",
     "@radix-ui/react-collapsible": "^1.1.12",
     "@radix-ui/react-dialog": "^1.1.15",
     "@radix-ui/react-separator": "^1.1.8",

pnpm-lock.yaml

@@ -17,6 +17,9 @@ importers:
       '@electron-toolkit/utils':
         specifier: ^4.0.0
         version: 4.0.0(electron@39.2.7)
+      '@fontsource/geist-sans':
+        specifier: ^5.2.5
+        version: 5.2.5
       '@radix-ui/react-collapsible':
         specifier: ^1.1.12
         version: 1.1.12(@types/react-dom@19.2.3(@types/react@19.2.8))(@types/react@19.2.8)(react-dom@19.2.3(react@19.2.3))(react@19.2.3)
@@ -670,6 +673,9 @@ packages:
   '@floating-ui/utils@0.2.10':
     resolution: {integrity: sha512-aGTxbpbg8/b5JfU1HXSrbH3wXZuLPJcNEcZQFMxLs3oSzgtVu6nFPkbbGGUvBcUjKV2YyB9Wxxabo+HEH9tcRQ==}
 
+  '@fontsource/geist-sans@5.2.5':
+    resolution: {integrity: sha512-anllOHyJbElRs9fV15TeDRqAeb1IKm4bSknPl6ZMoyPTx1BBy7logudcUwpNjmQLkzn4Q0JGQLRCUKJYoyST6A==}
+
   '@humanfs/core@0.19.1':
     resolution: {integrity: sha512-5DyQ4+1JEUzejeK1JGICcideyfUbGixgS9jNgex5nqkW+cY7WZhxBigmieN5Qnw9ZosSNVC9KQKyb+GUaGyKUA==}
     engines: {node: '>=18.18.0'}
@@ -4285,6 +4291,8 @@ snapshots:
 
   '@floating-ui/utils@0.2.10': {}
 
+  '@fontsource/geist-sans@5.2.5': {}
+
   '@humanfs/core@0.19.1': {}
 
   '@humanfs/node@0.16.7':

src/renderer/src/main.tsx

@@ -1,3 +1,4 @@
+import '@fontsource/geist-sans'
 import './styles/index.css'
 
 import { StrictMode } from 'react'

src/renderer/src/styles/index.css

@@ -10,14 +10,7 @@
 
 body {
   -webkit-font-smoothing: antialiased;
-  font-family:
-    -apple-system,
-    BlinkMacSystemFont,
-    'Segoe UI',
-    Roboto,
-    'Helvetica Neue',
-    Arial,
-    sans-serif;
+  font-family: 'Geist Sans', system-ui, sans-serif;
 }
 
 /* Draggable title bar region for macOS */