feat(ssh): add console configuration

[cjh1]

Adds the configuration foundation for managing SSH consoles directly in the service.

This is the first PR in a stack replacing the legacy ConMan SSH helper scripts with an in-process Go SSH console manager.

Overview

• feat(ssh): add console configuration #92 and feat(ssh): manage consoles in process #93 — SSH configuration and console management
• test(ssh): cover console behavior #94 and test(ssh): cover concurrency and scale #95 — Console behavior, concurrency, and scale tests
• refactor(console): encapsulate ConMan console I/O #110 through test(console): cover in-process console reconnects #112 — ConMan I/O encapsulation, in-process SSH routing, and integration coverage
• refactor(conman): remove legacy SSH console scripts #113 through fix(console): preserve session close behavior #116 — Legacy script removal and console refinements
• feat(ssh): format console logs #123 — Timestamped and sanitized console logs
• feat(ssh): wait for provisioned credentials #118 through fix(service): preserve complete inventory and credential views #121 — Credential, inventory, and process lifecycle hardening

Review the stack from #92 upward.