Add unit tests + cross-repo integration CI job

[zspitzer]

Summary

• Expand WebSocketClientTest.cfc from a single smoke test into a BDD-style suite (6 tests) covering: BIF loader/OSGi health, non-component listener rejection, wss:// scheme handling, http:// scheme rejection, connection-refused timing, 5s hardcoded connection-timeout enforcement.
• Add tests/README.md explaining the unit/integration split and the cross-repo setup.
• Workflow changes:
  • Deploy now gated on workflow_dispatch only (no more push-to-master auto-deploy).
  • New test-integration job sparse-checkouts tests/integration/ from the server repo, runs the full server-side integration suite against this branch's freshly-built client .lex + the latest published server .lex. Matrix is a minimal 6.2/stable + 7.0/stable × Java per Lucee version — the server repo owns the broader matrix.

Test plan

• Unit tests pass on 6.2 stable + snapshot × Java 11 + 21, and 7.0 stable + snapshot × Java 11 + 21 (8 combos)
• test-integration passes on 6.2/stable/jar and 7.0/stable/jar
• Deploy does not trigger on push, only on workflow_dispatch
• Full behavioural coverage via cross-repo integration (no duplication)

What's deliberately not tested here

• onError( type="connect", ... ) listener callback on sync TCP-connect failure: nv-websocket-client throws WebSocketException directly from blocking connect() without invoking the adapter's onConnectError in that path. The onError adapter hook only fires for async/mid-session failure modes, which aren't cheaply triggerable in unit tests.
• Round-trip send/receive / lifecycle / binary / disconnect — those live in extension-websocket's tests/integration/ and run here via the new cross-repo job.