Validate tokens.data.ts stays in sync with CreateIntentDto's supported chains

[james2177]

Description

CreateIntentDto hardcodes its own SUPPORTED_CHAINS array (src/intents/dto/create-intent.dto.ts) separately from SupportedChain in intents.types.ts and separately again from whatever chains actually have entries in src/tokens/tokens.data.ts — three independent sources of truth for "which chains are supported" that can silently drift.

Requirements and context

• Add a test (or better, refactor to a single source of truth) asserting all three stay consistent

Suggested execution

1. Fork the repo and create a branch

   git checkout -b fix/unify-supported-chains-source
   

2. Implement changes
   Relevant files:

• src/intents/dto/create-intent.dto.ts
• src/tokens/tokens.data.ts
• src/intents/intents.types.ts

3. Test and commit

   • Run npm run lint && npm run typecheck && npm test && npm run test:e2e
   • Include test output / screenshots or logs demonstrating the fix in the PR

   Example commit message:

   fix: unify supported-chains definitions across DTO, types, and token data
   

Guidelines

• Assignment required before starting — comment to claim this issue
• PR description must include: Closes #[this issue's number]
• Timeframe: 96 hours from assignment
• Complexity: High (200 points)

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Part of the Drips Wave for vortex-backend.