[#690] Logging refactored

[Crumby]

Closes #690

Summary

• Refactor logging across all controllers and pipeline handlers to use log.FromContext(ctx) instead of struct-level loggers, ensuring structured context (namespace, name, controller, reconcileID) is
  automatically included
• Replace fmt.Sprintf in log messages with structured key-value pairs using lowercase camelCase field keys
• Apply consistent log levels: V(1) for diagnostic/lifecycle messages, V(2) for deep debugging, Info for state-changing operations only
• Remove decorative log delimiters ("+++++ Reconciling", "----- End Reconciling")
• Eliminate double-logging by returning wrapped errors instead of logging then returning
• Rename struct loggers from log/Log to setupLog to clarify they are only for SetupWithManager use
• Normalize WithName to lowercase camelCase (e.g. "cache", "gossipRouter")
• Add logging conventions documentation to CONTRIBUTING.md

Test plan

• Verify operator builds cleanly (make build)
• Run unit tests (make test)
• Run e2e tests to confirm reconciliation behavior is unchanged
• Deploy operator and verify logs contain structured fields with correct context (namespace, name, reconcileID)
• Confirm no duplicate log lines appear for error paths
• Test interactions with logging env vars