feat: added metadata in app definition (#835)

[tesmarishy]

Pull Request

Summary

Provide a concise description of what this pull request does and why it is needed.

This is to add support for Metadata field in app definition. This is optional field. it can be passed empty. But if values are present, it should meet the schema values.

Issue

Link to the issue(s) this PR addresses (e.g., Fixes #123 or Closes #456). If no issue exists, explain why this change is necessary.

Breaking Change?

• Yes
• No

If yes, describe the breaking change and its impact (e.g., API changes, behavior changes, or required updates for users).

Scope / Project

Changes in appdef.schema.json

Implementation Notes

Provide details on how the change was implemented, including any technical considerations, trade-offs, or notable design decisions. Leave blank if not applicable.
Modified schema to accept metadata also if passed.

Tests / Evidence

Describe how the changes were verified, including:

• Tests added or updated (e.g., unit, integration, end-to-end)
• Manual testing steps or results
• Screenshots, logs, or other evidence (if applicable)

Additional Notes

Include any extra information, such as:

• Dependencies introduced
• Future work or follow-up tasks
• Reviewer instructions or context
• References to related PRs or discussions

Leave blank if not applicable.