fix: show usage when you run the help command

[PatrickSys]

Running codebase-context help started the server instead of showing help.
It now prints the existing usage text and exits, even if the project has a folder named help.
Tested: the regression failed before the fix; targeted and full tests, build, type checks, lint and formatting now pass.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-16T17:01:10.342732Z	2c411c7	PR opened

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[greptile-apps]

Confidence Score: 5/5

[Low impact] The PR appears safe to merge; no actionable issues were found.

Summary

Makes codebase-context help print the existing usage text instead of starting the server.

• The help command prints usage and exits without starting the server.

PatrickSys explicitly says that bare help should show usage even when that folder exists.

_{Reviews (1) · Last reviewed commit: "test: keep the original help response ti..." · Reviewed by Greptile}