Fix deprecated 'mode' attribute in prompt files by renaming to 'agent'

[Copilot]

Pull Request Checklist

• I have read and followed the CONTRIBUTING.md guidelines.
• My contribution adds a new instruction, prompt, or chat mode file in the correct directory.
• The file follows the required naming convention.
• The content is clearly structured and follows the example format.
• I have tested my instructions, prompt, or chat mode with GitHub Copilot.
• I have run npm start and verified that README.md is up to date.

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Description

VS Code reports lint error on prompt files: "The 'mode' attribute has been deprecated. Please rename it to 'agent'." per VS Code Copilot documentation.

Changes:

• Renamed mode to agent in all 108 prompt files
• Updated CONTRIBUTING.md example to reflect new attribute name
• Updated embedded examples in github-copilot-starter.prompt.md and prompt-builder.prompt.md

Before:

---
mode: 'agent'
description: 'Create a README.md file for the project'
---

After:

---
agent: 'agent'
description: 'Create a README.md file for the project'
---

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Type of Contribution

• New instruction file.
• New prompt file.
• New chat mode file.
• New collection file.
• Update to existing instruction, prompt, chat mode, or collection.
• Other (please specify):

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Additional Notes

Pre-existing quoting style inconsistencies (agent: 'agent' vs agent: agent) were preserved to maintain minimal diff.

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By submitting this pull request, I confirm that my contribution abides by the Code of Conduct and will be licensed under the MIT License.

Original prompt

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This section details on the original issue you should resolve

<issue_title>Getting Lint Error in prompt files</issue_title>
<issue_description>When used in vs code (latest version), getting error:

The 'mode' attribute has been deprecated. Please rename it to 'agent'.

This complies with the documentation:
https://code.visualstudio.com/docs/copilot/customization/prompt-files</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Getting Lint Error in prompt files #440

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[Copilot]

Pull request overview

This PR updates all prompt files (108 files) to comply with VS Code Copilot's latest documentation by renaming the deprecated mode attribute to agent in YAML front matter. The change prevents lint errors in VS Code and aligns with the official VS Code Copilot documentation.

Key changes:

• Renamed mode → agent in all 108 .prompt.md files
• Updated CONTRIBUTING.md example to reflect new attribute name
• Updated embedded examples in github-copilot-starter.prompt.md and prompt-builder.prompt.md

Reviewed changes

Copilot reviewed 107 out of 107 changed files in this pull request and generated 1 comment.

File	Description
prompts/*.prompt.md (108 files)	Renamed mode to agent in YAML front matter
CONTRIBUTING.md	Updated example prompt format to use agent attribute
prompts/github-copilot-starter.prompt.md	Updated embedded example to use agent attribute
prompts/prompt-builder.prompt.md	Updated template example to use agent attribute

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[Copilot]

The documentation comment suggests three possible values (agent, ask, edit), but based on VS Code documentation and the repository's actual usage, only agent and ask appear to be valid values for the agent field. The value edit doesn't appear to be used in any prompt files in this repository. Consider verifying if edit is a valid value and update the documentation accordingly, or remove it if it's not applicable.