Fix backend type-safety issues, contract workspace structure, and repo hygiene

[Young850]

• Remove all 36 remaining @ts-nocheck/@ts-ignore suppressions from backend/src by fixing the underlying type errors (noUncheckedIndexedAccess violations, duplicate declarations, zod v4 error-option API mismatch, missing Prisma models for the bridge indexer, undefined redisClient/pubClient references, and an Express router variable name collision in routes/index.ts) ([Backend] Reduce 39 TypeScript @ts-nocheck suppressions across backend #946)
• Fix ExplorerTransaction operation/asset type mismatch in blockExplorer.service.ts via a bounds-safe pick() helper ([Backend] Fix mismatched ExplorerTransaction type in blockExplorer.service.ts #962)
• Add missing src/lib.rs entry points for multisig_wallet_timelock and did_registry so every Cargo workspace member follows the same layout, and confirm content_management_system and all other members are fully populated ([Contracts] Add missing lib.rs files for workspace member contracts #969, [Contracts] content_management_system is listed as workspace member but directory is empty #970)
• Update .gitignore (root, backend, frontend) to exclude test snapshots, coverage output, and stray generated contract check/error files
  Closes [Backend] Reduce 39 TypeScript @ts-nocheck suppressions across backend #946
  Closes [Backend] Fix mismatched ExplorerTransaction type in blockExplorer.service.ts #962
  Closes [Contracts] Add missing lib.rs files for workspace member contracts #969
  Closes [Contracts] content_management_system is listed as workspace member but directory is empty #970

[vercel]

@Young850 is attempting to deploy a commit to the Ayomide Adeniran's projects Team on Vercel.

A member of the Team first needs to authorize it.

[drips-wave]

@Young850 Great news! 🎉 Based on an automated assessment of this PR, the linked Wave issue(s) no longer count against your application limits.

You can now already apply to more issues while waiting for a review of this PR. Keep up the great work! 🚀

Learn more about application limits

[ayomideadeniran]

Pr under

[ayomideadeniran]

Pr under review