🔒 Remove insecure environment variable fallback for API key

[linkalls]

🎯 What: Removed the environment variable fallbacks (process.env.JULES_API_KEY and process.env.EXPO_PUBLIC_JULES_API_KEY) from the apiKey initialization in constants/api-key-context.tsx.

⚠️ Risk: Directly passing environment variables into the initial state of the API key exposes the key directly on the client and in the source bundles, allowing unauthorized parties to access and misuse it.

🛡️ Solution: Replaced the insecure process.env fallback with an empty string (''). The component already effectively handles loading the saved key dynamically via SecureStore when the component mounts, so this removes the vulnerability without breaking functionality.

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PR created automatically by Jules for task 12295360081163404340 started by @linkalls

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[Copilot]

Pull request overview

Removes insecure client-side environment variable fallbacks for initializing the Jules API key, ensuring keys are only loaded from secure storage at runtime.

Changes:

• Removed process.env.JULES_API_KEY / process.env.EXPO_PUBLIC_JULES_API_KEY fallback from initial API key state.
• Initialized apiKey state to an empty string, relying on SecureStore loading on mount.

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