## Why
External-agent memory imports previously wrote only to the v1 workspace and queued only v1 consolidation, leaving the v2 pipeline without imported resources.
## What changed
- Always import selected resources into `memories_v2`. Also update `memories` when v1 is selected or a legacy workspace exists.
- Read `memories.version` for detection and import, detect pending changes across the applicable namespaces, and enqueue consolidation separately for each updated namespace.
- Combine project results across namespaces so cleanup in either can succeed while failures in either are reported.
- Adapt imported-memory consolidation instructions to the active pipeline's output format.
## Testing
Expand app-server integration coverage for v2 profiles, explicit v1 selection, default profiles, and existing legacy workspaces. Verify resource copies, consolidation queues, repeat detection, and cleanup of deleted or unscoped projects.
GitOrigin-RevId: 7e9206942d63fd55b7f2a7f5f9210b687da6a973
## What changed
- Move migration detection, import orchestration, models, and reporting from
`codex-app-server` into `codex-external-agent-migration`.
- Keep app-server protocol conversion in a dedicated boundary module.
- Organize source-specific configuration, sessions, hooks, plugins, commands,
subagents, and memory handling behind shared migration adapters.
- Relocate and split the migration tests alongside the extracted service.
GitOrigin-RevId: 3378ec2064806a28136d6ac98664ca1d75414a4e
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