docs(docker): document gateway tool-loop hard stops

[Sworntech-dev]

Summary

• Adds a Docker/gateway operator note for tool_loop_guardrails.hard_stop_enabled.
• Explains that the default warning-only behavior is reasonable for watched CLI/TUI sessions, but unattended gateway/server deployments may need explicit hard stops.
• Includes a short profile config example for enabling tool-loop circuit breakers.

Validation

• Manually checked the edited file for trailing whitespace.

Docs-only change; runtime behavior is unchanged.

References #46708

[alt-glitch]

Related: implements the docs request in #46708 (document hard_stop_enabled implications for gateway/server deployments). Also relates to #26015, which proposes flipping the default to enabled in code — different mechanism (docs/operator-note vs default change), so the maintainer can choose either or both.

[Sworntech-dev]

Thanks for the context.

Yes, that distinction makes sense. This PR is intentionally limited to the docs/operator-note path and does not change the default behavior.

If maintainers decide to flip the default through #26015, this note should still be useful for explaining the current/explicit gateway deployment behavior.

[teknium1]

Merged via PR #49944 (docs salvage cluster 2). Your commit was cherry-picked onto current main with your authorship preserved in git log — rebase-merged so it lands under your name. Thanks for the contribution!