Stabilize TradingView indicator CI tests

[Mathieu2301]

Summary

• Serialize the Node matrix jobs with max-parallel: 1 because the authenticated TradingView tests share the same session secrets.
• Give the MarketCipher B websocket study test the same 30s timeout as the SuperTrend strategy test.
• Wait for actual MarketCipher values before resolving the test promise.

Context

The post-merge Actions run for #316 no longer failed on SuperTrend. Node 14.x and 18.x timed out on Indicators > gets data from MarketCipher B study, while Node 19.x passed. That points to external TradingView websocket/session flakiness under concurrent matrix jobs rather than a deterministic code regression.

GitHub also reported a high vite Dependabot alert via vitest. npm audit proposes vitest@4.1.9, but that requires Node 20+, while this repo currently tests Node 14/18/19. I intentionally did not force that upgrade in this PR.

Validation

• npm test -- --run → 50 passed | 16 skipped

Signed-off-by: Nox nox@molted.net