infra: add linting and formatting for js projects (#230)

* wip

* wip

* wip

* format

* wip(mobile): lint and format

* cleanup

* nits

* nits

* idiomatic react

* nit

* format all root files

js/desktop/src/components/screen-source-picker.tsx

@@ -1,4 +1,4 @@
-import { useState, useEffect } from "react";
+import { useState, useEffect } from 'react';
 
 interface ScreenSourcePickerProps {
   title?: string;
@@ -9,8 +9,8 @@ interface ScreenSourcePickerProps {
 }
 
 export function ScreenSourcePicker({
-  title = "Select a screen",
-  confirmLabel = "Select",
+  title = 'Select a screen',
+  confirmLabel = 'Select',
   getSources,
   onSelect,
   onCancel,
@@ -23,18 +23,15 @@ export function ScreenSourcePicker({
     getSources().then((result) => {
       setSources(result);
       setLoading(false);
+      // Auto-select if there's only one source.
+      if (result.length === 1) {
+        setSelectedId(result[0].id);
+      }
     });
   }, [getSources]);
 
-  // Auto-select if there's only one source
-  useEffect(() => {
-    if (!loading && sources.length === 1) {
-      setSelectedId(sources[0].id);
-    }
-  }, [loading, sources]);
-
-  const screens = sources.filter((s) => s.id.startsWith("screen:"));
-  const windows = sources.filter((s) => s.id.startsWith("window:"));
+  const screens = sources.filter((s) => s.id.startsWith('screen:'));
+  const windows = sources.filter((s) => s.id.startsWith('window:'));
 
   return (
     <div className="absolute inset-0 z-50 flex items-center justify-center bg-black/90">
@@ -119,8 +116,8 @@ function SourceSection({
             onClick={() => onSelect(source.id)}
             className={`overflow-hidden rounded-lg border-2 text-left transition-colors ${
               selectedId === source.id
-                ? "border-blue-500 bg-zinc-800"
-                : "border-transparent bg-zinc-800/50 hover:border-zinc-600"
+                ? 'border-blue-500 bg-zinc-800'
+                : 'border-transparent bg-zinc-800/50 hover:border-zinc-600'
             }`}
           >
             <img