feat: add click-to-copy CopyableCode component across all detail pages

- New CopyableCode component with monospace styling and click-to-copy
- TaskDetailPage: copyable task code in header
- ProjectDetailPage: copyable project code in header
- MilestoneDetailPage: copyable milestone code in header
- MeetingDetailPage: copyable meeting code in header
- SupportDetailPage: copyable support code in header
- ProposeDetailPage: copyable propose code in header and info section

Helps users easily copy resource codes for CLI usage (hf task get <code>, etc)

src/pages/SupportDetailPage.tsx

@@ -2,6 +2,7 @@ import { useState, useEffect } from 'react'
 import { useParams, useNavigate } from 'react-router-dom'
 import api from '@/services/api'
 import { useAuth } from '@/hooks/useAuth'
+import CopyableCode from '@/components/CopyableCode'
 
 interface SupportItem {
   id: number
@@ -141,7 +142,7 @@ export default function SupportDetailPage() {
       <button className="btn-back" onClick={() => navigate(-1)}>← Back</button>
 
       <div className="task-header">
-        <h2>🎫 {support.support_code || `#${support.id}`}</h2>
+        <h2>🎫 {support.support_code ? <CopyableCode code={support.support_code} /> : `#${support.id}`}</h2>
         <div className="task-meta">
           <span className={`badge status-${support.status}`}>{support.status}</span>
           <span className={`badge priority-${support.priority}`}>{support.priority}</span>