[Feature]: Add input-based micro-agents to support template workflows

[xingyaoww]

What problem or use case are you trying to solve?
We need to extend micro-agents to support template-based workflows. Currently, micro-agents are triggered by keywords and inject specialized knowledge (e.g., GitHub API understanding). However, users often find themselves repeatedly typing similar prompts that could be templatized.

For example, a template for addressing PR comments could be a micro-agent that accepts inputs:

Can you look at this PR ${PR_URL}
And then check out to branch ${BRANCH_NAME} which corresponds to that PR
Then, read the diff against the main, understand the purpose of this PR, and then address the PR comments.
${USER_MESSAGE}

Describe the UX of the solution you'd like
Micro-agents would have two triggering mechanisms:

1. Traditional keyword-based triggers (e.g., .openhands_instruction)
2. UI-based selection where users can pick a micro-agent and provide required inputs via a form in FE

For future: If the user did NOT provide those inputs, the micro-agent itself can conversationally ask users for the required information.

Do you have thoughts on the technical implementation?

• Add an inputs parameter to the micro-agent system to specify required template variables
• Store micro-agent templates in the repository (e.g., in the existing micro-agents location)
• Add UI elements:
  • Button to create new micro-agent templates
  • "Save" button to automatically create PRs against the repository
• Future potential: Build an API to trigger these micro-agents (e.g., /start_session?workflow=resolve_issue)

Additional context
This enhancement maintains the existing micro-agent concept while adding template capabilities. Rather than creating separate systems for specialized knowledge injection and templated workflows, we're unifying them under the micro-agent framework with support for both keyword triggers and user-supplied inputs.

How's this revised version that maintains the micro-agent terminology while incorporating the template functionality?