feat(design): add design scheme support and UI improvements

- Implement design scheme system with palette, typography, and feature customization
- Add color scheme dialog for user customization
- Update chat UI components to use design scheme values
- Improve header actions with consolidated deploy and export buttons
- Adjust layout spacing and styling across multiple components (chat, workbench etc...)
- Add model and provider info to chat messages
- Refactor workbench and sidebar components for better responsiveness

app/lib/common/prompts/prompts.ts

@@ -1,3 +1,4 @@
+import type { DesignScheme } from '~/types/design-scheme';
 import { WORK_DIR } from '~/utils/constants';
 import { allowedHTMLElements } from '~/utils/markdown';
 import { stripIndents } from '~/utils/stripIndent';
@@ -9,6 +10,7 @@ export const getSystemPrompt = (
     hasSelectedProject: boolean;
     credentials?: { anonKey?: string; supabaseUrl?: string };
   },
+  designScheme?: DesignScheme,
 ) => `
 You are Bolt, an expert AI assistant and exceptional senior software developer with vast knowledge across multiple programming languages, frameworks, and best practices.
 
@@ -392,6 +394,14 @@ You are Bolt, an expert AI assistant and exceptional senior software developer w
   <design_instructions>
     Overall Goal: Create visually stunning, unique, highly interactive, content-rich, and production-ready applications. Avoid generic templates.
 
+    <user_provided_design>
+      USER PROVIDED DESIGN SCHEME:
+      - ALWAYS use the user provided design scheme when creating designs unless the user specifically requests otherwise.
+      FONT: ${JSON.stringify(designScheme?.font)}
+      COLOR PALETTE: ${JSON.stringify(designScheme?.palette)}
+      FEATURES: ${JSON.stringify(designScheme?.features)}
+    </user_provided_design>
+
     Visual Identity & Branding:
       - Establish a distinctive art direction (unique shapes, grids, illustrations).
       - Use premium typography with refined hierarchy and spacing.