feat: integrate Poimen LLM chat with reasoning model + deep technical depth

- Terminal: hook to api.riotpiao.com reasoning model with streaming
- Add markdown rendering via react-markdown + typography plugin
- Show thinking spinner (⠋⠙⠹⠸⠼⠴⠦⠧⠇⠏) + V100 32GB context during reasoning
- Interview-style help: cert rotation, Talos, SQS failover, vLLM, exactly-once, deploy root cause, K8s CRD
- Chat route: ultra-compressed caveman prompt (60% token reduction)
  - K8s deep expertise: CRDs, operators, reconciliation, Talos, Cilium
  - Cert management: cert-manager, 30d renewal, SOPS, Git audit trail
  - Multi-region queues: SQS FIFO, exactly-once, QueueTask CRD
  - AWS: CDK, CloudFormation, CloudWatch across 57+ regions
- Remove dark mode toggle button (system preference only)
- Update hire-me.png (dark/light auto-switch)
- Add tailwind typography for prose styling

components/Header.tsx

@@ -2,15 +2,15 @@
 
 import Link from 'next/link'
 import Image from 'next/image'
-import { Menu, X, Moon, Sun } from 'lucide-react'
-import { useState, useEffect } from 'react'
+import { Menu, X } from 'lucide-react'
+import { useState } from 'react'
 import { useTerminal } from '@/lib/TerminalContext'
 import { useLanguage } from '@/lib/LanguageContext'
 import { CIStatusIndicator } from './CIStatusIndicator'
 
 export default function Header() {
   const [open, setOpen] = useState(false)
-  const [dark, setDark] = useState(false)
+
   const [skillsOpen, setSkillsOpen] = useState(false)
   const [contactOpen, setContactOpen] = useState(false)
   const [educationOpen, setEducationOpen] = useState(false)
@@ -28,30 +28,7 @@ export default function Header() {
     setLang(lang === 'en' ? 'zh' : 'en')
   }
 
-  useEffect(() => {
-    const stored = localStorage.getItem('theme')
-    const prefersDark = window.matchMedia('(prefers-color-scheme: dark)').matches
-    const isDark = stored === 'dark' || (!stored && prefersDark)
-    
-    if (isDark) {
-      document.documentElement.classList.add('dark')
-    } else {
-      document.documentElement.classList.remove('dark')
-    }
-    setDark(isDark)
-  }, [])
 
-  const toggleDark = () => {
-    const newDark = !dark
-    if (newDark) {
-      document.documentElement.classList.add('dark')
-      localStorage.setItem('theme', 'dark')
-    } else {
-      document.documentElement.classList.remove('dark')
-      localStorage.setItem('theme', 'light')
-    }
-    setDark(newDark)
-  }
 
   return (
     <header className="sticky top-0 z-50 border-b border-gray-200 dark:border-gray-800 bg-white/95 dark:bg-gray-950/95 backdrop-blur">
@@ -219,9 +196,6 @@ export default function Header() {
                 </div>
               )}
             </div>
-            <button onClick={toggleDark} className="p-2 hover:bg-gray-100 dark:hover:bg-gray-800 rounded">
-              {dark ? <Sun size={20} /> : <Moon size={20} />}
-            </button>
             {/* Language Toggle */}
             <button 
               onClick={toggleLang}