Tighten doctor-workspace next-step guidance

[RichardGeorgeDavis]

Summary

Improve tools/scripts/doctor-workspace.sh so missing-tool output points to more actionable next steps.

Problem statement

The doctor script can identify missing tools, but the follow-up guidance can still be too generic. For a new contributor, the useful question is not just "what is missing?" but "what should I do next?"

Affected area

• tools/scripts/doctor-workspace.sh
• Related setup docs if needed

Expected outcome

Make the output more actionable for common setup gaps such as:

• Node.js missing
• pnpm missing
• gh missing
• optional mixed-stack tools missing

The output should point to the right next command or doc path where practical.

Constraints or non-goals

• Keep the script non-destructive
• Do not turn the doctor into an installer
• Avoid broad refactors unrelated to user guidance

Verification

• Run the doctor in a controlled environment or fixture
• Confirm missing-tool output points to a useful next step
• Confirm any referenced docs or commands are valid