FIX: OSS Repo Cleanup and Cloud Credit Check Bug Fix

[tahierhussain]

What

• Remove cloud-only 1prod.py settings file that was mistakenly committed to the OSS repo
• Simplify README getting started instructions
• Fix bug where credit check was silently bypassed in cloud mode

Why

• 1prod.py is a cloud-only configuration file and should not be in the public OSS repository
• README was verbose; simplified for better developer experience
• The except Exception: pass block was swallowing InsufficientTokenBalance exceptions, allowing AI requests to proceed even when users had exhausted their credits

How

• Deleted backend/backend/server/settings/1prod.py
• Condensed README getting started section using collapsible details
• Changed except Exception: to except ImportError: in fetch_token_balance() so only the import error (for OSS mode) is caught, while InsufficientTokenBalance propagates correctly

Can this PR break any existing features. If yes, please list possible items. If no, please explain why. (PS: Admins do not merge the PR without this section filled)

• No breaking changes for OSS users - The 1prod.py file was never used in OSS mode, and the credit check fix only affects cloud deployments
• Cloud mode fix - Users who exhausted credits will now correctly be blocked from making AI requests (this is the intended behavior)

Database Migrations

• None

Env Config

• None

Relevant Docs

• N/A

Related Issues or PRs

• N/A

Dependencies Versions

• No changes

Notes on Testing

• OSS mode: Verify AI requests work without pluggable_apps installed (ImportError is caught, billing skipped)
• Cloud mode: Verify that users with zero credits receive InsufficientTokenBalance error and cannot make AI requests

Screenshots

Checklist

I have read and understood the Contribution Guidelines.

[abhizipstack]

LGTM