Editing a bundled agent is undone on restart

[Ju-usc]

Before filing

• I searched open and closed issues for duplicates.
• I reproduced this on the latest release.
• This is one bug, not several bundled together.

Closest existing issue

none found

What is broken

Harness and model settings saved for a bundled agent are replaced by the packaged defaults the next time Berd starts.

Steps to reproduce

1. Launch Berd.
2. Open Agents and edit a bundled agent.
3. Select a harness and model, then wait for the edit to save.
4. Quit and reopen Berd.
5. Reopen that agent.

What you expected to happen

The selected harness and model persist across restarts.

What actually happened

The agent returns to its packaged configuration and the saved provider, modelProviderId, and model fields disappear.

How often does it happen?

Every time — reliably reproducible when a previously seeded bundled agent differs from its packaged copy.

Berd version

0.6.2

Operating system

macOS 26.5.2, Apple Silicon

Model and provider

n/a — this occurs in agent configuration before any chat turn.

Relevant log output

[2026-08-20][05:45:47][berd_lib][INFO] Seeded 7 bundled agent(s)

Screenshots, recordings, or other context

The editor preserves metadata.berdBundled: true. At startup, should_install_agent refreshes any previously seeded, still-marked file whose bytes differ from the packaged source. install_agent_file then atomically replaces the edited file. The repository test replaces_edited_seeded_agent_before_launch confirms this behavior.

User-owned routing fields need to survive bundled-agent refresh, or editing a bundled agent should convert it to a personal copy.