feat: 3-role auth, role-based routing, role-specific sidebar navigation

Add cc-agent role alongside executive and admin. Login page now has 3 tabs
(Marketing Executive, Call Center, Admin). RoleRouter renders the appropriate
home page per role. Sidebar shows completely different nav items per role with
role subtitle. Placeholder pages added for Team Dashboard, Call Desk, Call
History, and Follow-ups.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/providers/auth-provider.tsx

@@ -1,7 +1,7 @@
 import type { ReactNode } from 'react';
 import { createContext, useContext, useState } from 'react';
 
-export type Role = 'executive' | 'admin';
+export type Role = 'executive' | 'admin' | 'cc-agent';
 
 type User = {
     name: string;
@@ -14,6 +14,7 @@ type AuthContextType = {
     user: User;
     setRole: (role: Role) => void;
     isAdmin: boolean;
+    isCCAgent: boolean;
     isAuthenticated: boolean;
     login: () => void;
     logout: () => void;
@@ -32,6 +33,12 @@ const USERS: Record<Role, User> = {
         role: 'executive',
         email: 'sanjay@ramaiah.com',
     },
+    'cc-agent': {
+        name: 'Rekha S.',
+        initials: 'RS',
+        role: 'cc-agent' as const,
+        email: 'rekha@ramaiah.com',
+    },
 };
 
 const AuthContext = createContext<AuthContextType | undefined>(undefined);
@@ -56,12 +63,13 @@ export const AuthProvider = ({ children }: AuthProviderProps) => {
 
     const user = USERS[role];
     const isAdmin = role === 'admin';
+    const isCCAgent = role === 'cc-agent';
 
     const login = () => setIsAuthenticated(true);
     const logout = () => setIsAuthenticated(false);
 
     return (
-        <AuthContext.Provider value={{ user, setRole, isAdmin, isAuthenticated, login, logout }}>
+        <AuthContext.Provider value={{ user, setRole, isAdmin, isCCAgent, isAuthenticated, login, logout }}>
             {children}
         </AuthContext.Provider>
     );