Add multiple account support

[Copilot]

Enables users to authenticate with multiple GitHub accounts simultaneously and switch between them. Each account maintains isolated data and cache.

Implementation

Account Management (services/accountService.ts)

• CRUD operations for accounts stored in localStorage
• Auto-migration from legacy single-account storage
• Account structure: { id, token, user, addedAt }

Cache Isolation (services/cacheService.ts)

• Namespace cache keys by account ID: vibe_github_cache_{accountId}_{key}
• Enhanced clearCache() with account-specific cleanup modes
• Prevents cross-account data leakage

Account Switcher UI (components/AccountSwitcher.tsx)

• Dropdown showing all accounts with avatars
• Active account indicator, per-account removal
• Accessible with keyboard navigation and ARIA labels

State Refactoring (App.tsx)

• Changed from single token/user to accounts/activeAccount
• Navigation reset on account switch
• Cleanup on account removal and sign-out

Usage

// Switch accounts
handleSwitchAccount('username');

// Remove account (clears associated cache)
handleRemoveAccount('username');

// Sign out all (clears all accounts and cache)
handleLogout();

Screenshots

Account Switcher

Shows active account indicator, remove buttons on hover/focus, and add account option.

Migration
Existing users automatically migrated on first load - legacy gh_token/gh_user converted to new account system with cleanup of old storage.

Security

• Complete data isolation per account
• Proper token cleanup on removal
• CodeQL scan: 0 vulnerabilities

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Add support for multiple accounts</issue_title>
<issue_description></issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Add support for multiple accounts #19

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[github-actions]

🚀 Netlify Deployment

Deploy URL: https://694ac1c491fdb80ca47bc70f--my-test-site3.netlify.app

Branch: copilot/add-support-for-multiple-accounts-again
Commit: 98140d0

[github-actions]

🚀 Netlify Deployment

Deploy URL: https://694ac1c74d013e0b8a54a742--my-test-site3.netlify.app

Branch: copilot/add-support-for-multiple-accounts-again
Commit: ffe5e9e

[github-actions]

🚀 Netlify Deployment

Deploy URL: https://694ac1c357fa50367f56abb7--my-test-site3.netlify.app

Branch: copilot/add-support-for-multiple-accounts-again
Commit: fa3ffc7

[github-actions]

🚀 Netlify Deployment

Deploy URL: https://694ac1c86eaebd0dde46aaf9--my-test-site3.netlify.app

Branch: copilot/add-support-for-multiple-accounts-again
Commit: 2a0d7a8