Allow users to customize preset agents

[boycez]

Summary

Allow users to edit the agents that MicroClaw provides by default. Preset agents should remain ready to use out of the box, while also serving as customizable starting points rather than fixed, read-only definitions.

Proposed experience

Add an Edit agent action for each preset agent. Users should be able to customize fields such as:

• Avatar
• Display name
• Description
• Identity or role
• Persona, tone, and communication style
• Instructions or behavioral guidance
• Other agent metadata already supported by the underlying agent model

Changes should be previewable before saving and should take effect consistently wherever the agent appears in the app.

Default and reset behavior

• Ship each preset agent with a complete, useful default configuration.
• Preserve the original preset so users can restore an agent to its defaults.
• Clearly distinguish user-customized values from product defaults.
• Handle product updates without silently overwriting user customizations.
• Consider a duplicate or Save as new agent action when users want to retain both the original preset and their variation.

Why this matters

Preset agents make onboarding fast, but fixed identities and personas limit their usefulness across different workflows, teams, and personal preferences. Editable presets provide immediate value for new users while giving experienced users control over how their agents look, communicate, and behave.

Acceptance criteria

• A user can edit and save the supported presentation and persona fields of a preset agent.
• Saved changes persist across app restarts.
• Customized agents are reflected consistently throughout the UI and during conversations.
• A user can restore the original preset configuration.
• App updates do not unexpectedly discard user customizations.