fix: resolve Web UI display issues (#365)

## Fixes
### 1. Typewriter Component - Missing First Character
- Fix character loss issue where first character of each line was missing
- Add proper state reset logic before starting typing animation
- Extract character before setState to avoid closure issues
- Add setTimeout(0) to ensure state is updated before typing starts
- Change dependency from `lines` to `sanitizedLines` for correct updates
- Use `??` instead of `||` for safer null handling
### 2. Chinese Translation - Leading Spaces
- Remove leading spaces from startupMessages1/2/3 in Chinese translations
- Ensures proper display of startup messages in terminal simulation
### 3. Dynamic GitHub Stats with Animation
- Add useGitHubStats hook to fetch real-time GitHub repository data
- Add useCounterAnimation hook with easeOutExpo easing for smooth number animation
- Display dynamic star count with smooth counter animation (2s duration)
- Display dynamic days count (static, no animation)
- Support bilingual display (EN/ZH) with proper formatting
## Changes
- web/src/components/Typewriter.tsx: Fix first character loss bug
- web/src/i18n/translations.ts: Remove leading spaces in Chinese messages
- web/src/components/landing/HeroSection.tsx: Add dynamic GitHub stats
- web/src/hooks/useGitHubStats.ts: New hook for GitHub API integration
- web/src/hooks/useCounterAnimation.ts: New hook for number animations
Fixes #365
Co-Authored-By: tinkle-community <tinklefund@gmail.com>

web/src/hooks/useGitHubStats.ts

@@ -0,0 +1,61 @@
+import { useState, useEffect } from 'react'
+
+interface GitHubStats {
+  stars: number
+  forks: number
+  createdAt: string
+  daysOld: number
+  isLoading: boolean
+  error: string | null
+}
+
+export function useGitHubStats(owner: string, repo: string): GitHubStats {
+  const [stats, setStats] = useState<GitHubStats>({
+    stars: 0,
+    forks: 0,
+    createdAt: '',
+    daysOld: 0,
+    isLoading: true,
+    error: null,
+  })
+
+  useEffect(() => {
+    const fetchGitHubStats = async () => {
+      try {
+        const response = await fetch(`https://api.github.com/repos/${owner}/${repo}`)
+
+        if (!response.ok) {
+          throw new Error('Failed to fetch GitHub stats')
+        }
+
+        const data = await response.json()
+
+        // Calculate days since creation
+        const createdDate = new Date(data.created_at)
+        const now = new Date()
+        const diffTime = Math.abs(now.getTime() - createdDate.getTime())
+        const diffDays = Math.ceil(diffTime / (1000 * 60 * 60 * 24))
+
+        setStats({
+          stars: data.stargazers_count,
+          forks: data.forks_count,
+          createdAt: data.created_at,
+          daysOld: diffDays,
+          isLoading: false,
+          error: null,
+        })
+      } catch (error) {
+        console.error('Error fetching GitHub stats:', error)
+        setStats(prev => ({
+          ...prev,
+          isLoading: false,
+          error: error instanceof Error ? error.message : 'Unknown error',
+        }))
+      }
+    }
+
+    fetchGitHubStats()
+  }, [owner, repo])
+
+  return stats
+}