fix: resolve duplicate header and improve Redis management

- Dashboard: Remove redundant header (Layout already provides it)
- projectctl.sh: Add start_redis/stop_redis functions for automatic
  Redis lifecycle management on project start/stop
- rate_limiter.py: Add fallback to memory storage when Redis unavailable

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/src/pages/Dashboard.tsx

@@ -1,95 +1,34 @@
 import { useAuth } from '../contexts/AuthContext'
 
 export default function Dashboard() {
-  const { user, logout } = useAuth()
-
-  const handleLogout = async () => {
-    await logout()
-  }
+  const { user } = useAuth()
 
   return (
     <div style={styles.container}>
-      <header style={styles.header}>
-        <h1 style={styles.title}>Project Control</h1>
-        <div style={styles.userInfo}>
-          <span style={styles.userName}>{user?.name}</span>
-          {user?.is_system_admin && (
-            <span style={styles.badge}>Admin</span>
-          )}
-          <button onClick={handleLogout} style={styles.logoutButton}>
-            Logout
-          </button>
-        </div>
-      </header>
-
-      <main style={styles.main}>
-        <div style={styles.welcomeCard}>
-          <h2>Welcome, {user?.name}!</h2>
-          <p>Email: {user?.email}</p>
-          <p>Role: {user?.role || 'No role assigned'}</p>
-          {user?.is_system_admin && (
-            <p style={styles.adminNote}>
-              You have system administrator privileges.
-            </p>
-          )}
-        </div>
-
-        <div style={styles.infoCard}>
-          <h3>Getting Started</h3>
-          <p>
-            This is the Project Control system dashboard. Features will be
-            added as development progresses.
+      <div style={styles.welcomeCard}>
+        <h2>Welcome, {user?.name}!</h2>
+        <p>Email: {user?.email}</p>
+        <p>Role: {user?.role || 'No role assigned'}</p>
+        {user?.is_system_admin && (
+          <p style={styles.adminNote}>
+            You have system administrator privileges.
           </p>
-        </div>
-      </main>
+        )}
+      </div>
+
+      <div style={styles.infoCard}>
+        <h3>Getting Started</h3>
+        <p>
+          This is the Project Control system dashboard. Features will be
+          added as development progresses.
+        </p>
+      </div>
     </div>
   )
 }
 
 const styles: { [key: string]: React.CSSProperties } = {
   container: {
-    minHeight: '100vh',
-    backgroundColor: '#f5f5f5',
-  },
-  header: {
-    display: 'flex',
-    justifyContent: 'space-between',
-    alignItems: 'center',
-    padding: '16px 24px',
-    backgroundColor: 'white',
-    boxShadow: '0 1px 3px rgba(0, 0, 0, 0.1)',
-  },
-  title: {
-    fontSize: '20px',
-    fontWeight: 600,
-    color: '#333',
-    margin: 0,
-  },
-  userInfo: {
-    display: 'flex',
-    alignItems: 'center',
-    gap: '12px',
-  },
-  userName: {
-    color: '#666',
-  },
-  badge: {
-    backgroundColor: '#0066cc',
-    color: 'white',
-    padding: '2px 8px',
-    borderRadius: '4px',
-    fontSize: '12px',
-    fontWeight: 500,
-  },
-  logoutButton: {
-    padding: '8px 16px',
-    backgroundColor: '#f5f5f5',
-    border: '1px solid #ddd',
-    borderRadius: '4px',
-    cursor: 'pointer',
-    fontSize: '14px',
-  },
-  main: {
     padding: '24px',
     maxWidth: '1200px',
     margin: '0 auto',