refactor(create-expert): reduce template redundancy in ecosystem-builder

[FL4TLiN3]

Summary

Extracts common error format to a single definition and simplifies ecosystem-builder templates.

Changes

1. Added shared error format section:

## Error Format (all ecosystem experts)

All errors must follow this format:
❌ [Type]: [description] | To fix: [actionable steps]

Where [Type] is: Error, Failed, or Issue depending on context.

2. Simplified templates:

   • Removed duplicate error handling sections from each template
   • Templates now reference "standard error format" instead of repeating it
   • Reduced verbose explanations

3. Removed time-based criterion:

   • "Setup expert should complete in < 2 minutes" (untestable)

Before/After comparison

Before (Setup template):

## Error Handling
When setup fails, guide the user:
- "❌ Failed: [what went wrong] | To fix: [specific steps]"
- Suggest running the doctor expert for diagnostics

After (Setup template):

## On Failure
Suggest running <name>-doctor for diagnostics.

(Error format is now defined once in the shared section)

Closes #381

Test plan

• CI passes
• No behavior changes expected (templates simplified, same intent)

---

Note

Consolidates error handling and simplifies templates in ecosystem-builder.

• Adds shared "## Error Format (all ecosystem experts)" section and instructs all experts to use it
• Simplifies Main, Demo, Setup, and Doctor templates: remove duplicated error-handling text, tighten wording, and standardize sections (e.g., "Output"/"On Failure")
• Updates Design Principles: require the standard error format; remove time-based setup target (<2 minutes)
• Changes limited to apps/create-expert/src/lib/create-expert-toml.ts and a patch changeset; no runtime behavior changes

^{Written by Cursor Bugbot for commit 47e4211. This will update automatically on new commits. Configure here.}

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!

[cursor]

Doctor template references undefined "standard error format"

The doctor expert template instruction says "Use standard error format" but this references a definition (lines 122-130) that only exists in the ecosystem-builder's meta-instructions. When an actual <name>-doctor expert is created from this template, its instruction won't include what "standard error format" means since that definition is outside the template's instruction = '''...''' block. The original code explicitly included the format inline: "❌ Issue: [problem] | To fix: [steps]".

 

[cursor]

Setup template removes error format guidance entirely

The setup expert template's "On Failure" section now only instructs to suggest running the doctor expert, but completely omits guidance on how to format the error message itself. The original template explicitly included "❌ Failed: [what went wrong] | To fix: [specific steps]" before suggesting the doctor. Unlike the doctor template which at least references "standard error format", this template has no error formatting instruction at all, meaning created setup experts may not report failures in the expected format.