feat: change dashboard tool result colors from green to purple (#133)

- Updated CSS variables for tool result styling in both light and dark themes
- Light theme: background #f3e8ff, border #9333ea (previously green tones)
- Dark theme: background #4c1d95, border #9333ea (previously green tones)
- Updated test expectations to match new color values
- Maintains WCAG AA accessibility compliance with excellent contrast ratios

Author: crystalin

services/dashboard/src/layout/__tests__/styles.test.ts

@@ -131,12 +131,12 @@ describe('Dark Mode CSS Variables', () => {
     expect(lightVars['--msg-user-bg']).toBe('#eff6ff')
     expect(lightVars['--msg-assistant-bg']).toBe('#ffffff')
     expect(lightVars['--msg-tool-use-bg']).toBe('#fef3c7')
-    expect(lightVars['--msg-tool-result-bg']).toBe('#dcfce7')
+    expect(lightVars['--msg-tool-result-bg']).toBe('#f3e8ff')
 
     // Dark theme message colors
     expect(darkVars['--msg-user-bg']).toBe('#1e3a8a')
     expect(darkVars['--msg-assistant-bg']).toBe('#1e293b')
     expect(darkVars['--msg-tool-use-bg']).toBe('#78350f')
-    expect(darkVars['--msg-tool-result-bg']).toBe('#14532d')
+    expect(darkVars['--msg-tool-result-bg']).toBe('#4c1d95')
   })
 })

services/dashboard/src/layout/styles.ts

@@ -56,8 +56,8 @@ export const dashboardStyles = `
     --msg-system-border: #9ca3af;
     --msg-tool-use-bg: #fef3c7;
     --msg-tool-use-border: #f59e0b;
-    --msg-tool-result-bg: #dcfce7;
-    --msg-tool-result-border: #22c55e;
+    --msg-tool-result-bg: #f3e8ff;
+    --msg-tool-result-border: #9333ea;
     
     /* Code block colors */
     --code-bg: #1e293b;
@@ -117,8 +117,8 @@ export const dashboardStyles = `
     --msg-system-border: #6b7280;
     --msg-tool-use-bg: #78350f;
     --msg-tool-use-border: #f59e0b;
-    --msg-tool-result-bg: #14532d;
-    --msg-tool-result-border: #22c55e;
+    --msg-tool-result-bg: #4c1d95;
+    --msg-tool-result-border: #9333ea;
     
     /* Code block colors */
     --code-bg: #0f172a;