Make backend modules environment-gated through configuration instead of `process.env`

[grantfox-oss]

AppModule conditionally loads reconciliation, notifications, and developer modules based on raw SUPABASE_URL string checks. This makes behavior surprising across test, local, staging, and production environments.

Affected areas: app/backend/src/app.module.ts, app/backend/src/config/*, app/backend/src/reconciliation/*, app/backend/src/notifications/*, app/backend/src/developer/*, .env.example, backend setup docs/tests.

Implementation scope:

• Add typed config flags such as features.reconciliationEnabled, features.notificationsEnabled, and features.developerRoutesEnabled.
• Move dynamic module selection behind a small factory with tests.
• Document safe local defaults and production-required settings.
• Remove direct process.env reads from module composition.

Acceptance criteria:

• Test, local, staging, and production module sets are deterministic from typed config.
• Missing required production config fails fast.
• Docs and .env.example describe each flag and default.

[somgoli]

Hi, i just reviewed the issue description and will like to work on this. ETA: 5hours. Thank you

[shadrach68]

I would like to work on this issue because I am a full-stack developer with 5+ years experience. I focus on identifying root causes and delivering clean, efficient, and maintainable solutions, with thorough testing to ensure reliable results.

[Nemenwq]

Hi maiantainer, i just reviewed the issue details and will like to work on this. ETA: 6hours

[Nemenwq]

Hi maiantainer, i just reviewed the issue details and will like to work on this. ETA: 6hours

[Biokes]

Hi maintainer,
I'm a Software Engineer and I'd like to take this issue. I understand the requirements and will follow the existing project structure, keep the implementation clean, and include proper tests where applicable.

[grantfox-oss]

🦊 GrantFox — @Nemenwq has been assigned to this issue as part of the Official Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #6)
2. Your PR will be reviewed by the BlockDash-Studios maintainers

Good luck! Track your progress on GrantFox.

[grantfox-oss]

🎉 This issue has been marked as completed on GrantFox!

@Nemenwq's PR #46 was approved and merged by @Nabeelahh.

🏆 @Nemenwq: You earned 35 FoxPoints for this contribution! Your current tier: Explorer (576 total points). Track your full progress on GrantFox.

👏 Great work, @Nemenwq! Keep contributing to BlockDash-Studios.