fix(sec): update npm deps to resolve npm audit warnings

pin brace-expansion to 5.0.8
update concurrently to 10.0.4
update electron-builder to 26.15.3
update eslint to 10.8.0
update eslint-plugin-perfectionist to 5.10.0
update @assistant-ui/react to 0.15.0
update @assistant-ui/react-streamdown to 0.3.8
update radix-ui to 1.6.7
update react-router-dom to react-router@8.3.0 - react-router-dom is no longer a standalone package, it just reexports react-router
remove @radix-ui/react-slot: we import this from `radix-ui`
remove eslint-plugin-react: we imported it, but never actually used it!

eslint.config.shared.mjs

@@ -15,7 +15,6 @@ import js from '@eslint/js'
 import typescriptEslint from '@typescript-eslint/eslint-plugin'
 import typescriptParser from '@typescript-eslint/parser'
 import perfectionist from 'eslint-plugin-perfectionist'
-import reactPlugin from 'eslint-plugin-react'
 import hooksPlugin from 'eslint-plugin-react-hooks'
 import unusedImports from 'eslint-plugin-unused-imports'
 import globals from 'globals'
@@ -41,7 +40,6 @@ export default [
     plugins: {
       '@typescript-eslint': typescriptEslint,
       perfectionist,
-      react: reactPlugin,
       'react-hooks': hooksPlugin,
       'unused-imports': unusedImports
     },
@@ -95,9 +93,6 @@ export default [
       'react-hooks/exhaustive-deps': 'warn',
       'react-hooks/rules-of-hooks': 'error',
       'unused-imports/no-unused-imports': 'error'
-    },
-    settings: {
-      react: { version: 'detect' }
     }
   },
   {