chore(help): simplify command indexes

[notgitika]

Summary

• use the documented Commander subcommandTerm formatter to show command names only
• remove options, arguments, and subcommand syntax from parent command indexes
• keep the complete invocation grammar in each command-specific Usage: line

This makes every command index consistent and easier to scan without changing parsing or command-specific help.

Example

Before:

Commands:
  create [options]             create a new AgentCore project
  add                          add project resources
  remove [options] [resource]  remove a resource from the project

After:

Commands:
  create  create a new AgentCore project
  add     add project resources
  remove  remove a resource from the project

agentcore project remove --help still shows Usage: agentcore project remove [options] [resource].

Testing

• bun test src/router/router.test.ts
• bun run typecheck
• bun run lint:check
• bun run format:check
• full suite reached 2,901 passing tests; the local Bun 1.3.6 fallback install then stopped on a missing nested CDK fixture dependency because it cannot parse the branch lockfile version

[agentcore-devx-automation]

Claude Security Review: no high-confidence findings. (run)

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.04%. Comparing base (da28031) to head (07e5d89).

Additional details and impacted files

@@            Coverage Diff            @@
##           refactor    #2219   +/-   ##
=========================================
  Coverage     97.04%   97.04%           
=========================================
  Files           544      544           
  Lines         37536    37537    +1     
=========================================
+ Hits          36428    36429    +1     
  Misses         1108     1108           

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[agentcore-devx-automation]

Claude Security Review: no high-confidence findings. (run)

[agentcore-devx-automation]

Claude Security Review: no high-confidence findings. (run)

[agentcore-devx-automation]

AgentCore Harness Review

Verdict: Looks good

Small, well-scoped change that overrides Commander's subcommandTerm so the command index shows just names instead of the full name [options] <args> signature. Behavior:

• Usage: line is untouched (still shows [options] [command]), which the test asserts.
• Subcommand entries drop [options], positional args, and the [command] marker on groups.

The test uses real Router/Commander instances and covers the three interesting cases (flags, positional args, nested groups). No mocking concerns, and no telemetry is warranted for a help-formatting change. Nothing blocking — all substantive points were already covered by the prior automated review.