HotFix: Fix Debug Auth Bug

[kiyarose]

This pull request updates the debug-mode Firebase authentication flow to require a custom token for cloud access, ensuring that debug builds are local-only unless explicitly configured. It also improves documentation and adds a feature flag check to prevent accidental cloud access during development.

Debug Firebase authentication changes:

• src/shared/firebase/DebugAuthProvider.tsx: Refactored to remove anonymous sign-in; debug mode now only signs in with VITE_DEBUG_FIREBASE_CUSTOM_TOKEN for fixed uid DEBUGGER. If no token is set, Firebase/cloud features are disabled in debug mode. [1] [2]
• src/shared/features/featureFlags.ts: Added a check in isFirebaseEnabled() to disable Firebase in debug mode unless a custom token is provided, with a warning in the console.

Documentation updates:

• .env.local.example: Clarified that VITE_DEBUG_FIREBASE_CUSTOM_TOKEN is required for debug mode Firebase and that leaving it blank keeps debug builds local-only.
• docs/FIREBASE.md: Updated to reflect that debug Firebase is local-only/off unless a custom token is set, and clarified the authentication flow in debug mode.
• AGENTS.md: Updated the description of DebugAuthProvider to match the new behavior—debug mode only signs in with a custom token, otherwise disables cloud features.

[Copilot]

Pull request overview

Updates the debug-mode Firebase authentication flow so debug builds don’t access Firebase/cloud services unless explicitly configured with a custom token, and documents the new behavior to reduce accidental cloud usage during development.

Changes:

• Reworked debug auth to require VITE_DEBUG_FIREBASE_CUSTOM_TOKEN (removing anonymous sign-in) and sign in via signInWithCustomToken.
• Updated Firebase feature-flag evaluation to disable Firebase in debug mode when no debug custom token is configured (with a dev-only warning).
• Refreshed documentation and examples to reflect “local-only unless token is set” behavior.

Reviewed changes

Copilot reviewed 5 out of 6 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/shared/firebase/DebugAuthProvider.tsx	Removes anonymous debug sign-in and requires a custom token for debug sessions.
src/shared/features/featureFlags.ts	Disables Firebase in debug mode unless a debug custom token is present; adds warning.
docs/FIREBASE.md	Documents the new debug-only custom token requirement and flow.
AGENTS.md	Updates internal contributor notes to match new debug auth behavior.
.env.local.example	Clarifies that debug Firebase requires a custom token; blank keeps debug local-only.
.gitignore	Ignores /scripts/emergency.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.