docs: Add missing configuration documentation

[munishchouhan]

Summary

• Document ~20 previously undocumented configuration options in docs/configuration.md including: wave.denyHosts, K8s DNS policy/servers, platform-specific node selectors, scan
  status duration, container mirror K8s resources, proxy cache settings, rate-limit timeout errors, license server URL, and advanced operational settings (job manager, message
  stream, thread monitor, trace slow endpoint)

Test plan

• All documented config options verified to exist in the codebase with matching default values

[christopher-hakkaart]

Hi @munishchouhan, your additions look good.

I've used this PR to update the page's style, standardize language and formatting, and fix a couple of indentation issues. I also moved some of the more instructional content to the configure-wave page, as it's guided content rather than a reference list. This wasn't a part of this PR, but while I was on the page, I moved it.