Activate an Implemented but Unused Read-Through Cache Decorator on Stellar Service Calls

[Emmyt24]

Description

backend/src/stellar-service-integration/stellar-read-cache.ts and stellar-cache.decorator.ts implement a fully unit-tested read-through caching layer, but @CacheStellarRead is never applied to any method on StellarService (getTokenInfo, getFactoryState, getTransaction, etc.) — the caching layer is dead code and every read still hits the RPC directly.

Requirements and Context

• Apply the decorator only to genuinely cacheable, read-only methods
• Confirm cache invalidation behaves correctly once the decorator is actually exercised by real call sites

Suggested Execution

Branch: feat/integration-activate-stellar-read-cache

Implement Changes

• Apply @CacheStellarRead to the appropriate read-only methods on StellarService (getTokenInfo, getFactoryState, getTransaction)
• Confirm the existing cache invalidation logic behaves correctly once real call sites are decorated
• Add a test asserting a repeated call within the cache window doesn't re-hit the RPC client

Test and Commit

Run npx vitest run src/__tests__/stellarReadCache.integration.test.ts — a repeated read within the cache window is served from cache instead of re-hitting the RPC client.

Example Commit Message

feat(backend): apply the read-through cache decorator to stellar service read methods

Closes #<issue>

Guidelines

• Branch from main, open a PR back to main
• All new code must have corresponding tests
• Run npm run lint and npm run test before pushing
• Follow existing naming conventions and file structure
• PR description must reference this issue number (e.g., Closes #<issue>)
• Keep commits atomic and use conventional commit format