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+# Foundry Agent Handoff
+
+## Baseline
+
+- Repo: `rivet-dev/sandbox-agent`
+- Branch: `columbus-v2`
+- Last pushed commit: `3174fe73` (`feat(foundry): checkpoint actor and workspace refactor`)
+- Progress/spec tracker: [FOUNDRY-CHANGES.md](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/FOUNDRY-CHANGES.md)
+
+## What is already landed
+
+These spec slices are already implemented and pushed:
+
+- Item `1`: backend actor rename `auth-user` -> `user`
+- Item `2`: Better Auth mapping comments
+- Item `5`: task raw SQL cleanup into migrations
+- Item `6`: `history` -> `audit-log`
+- Item `7`: default model moved to user-scoped app state
+- Item `20`: admin action prefixing
+- Item `23`: dead `getTaskEnriched` / `enrichTaskRecord` removal
+- Item `25`: `Workbench` -> `Workspace` rename across backend/shared/client/frontend
+- Item `26`: branch rename deleted
+- Organization realtime was already collapsed to full-snapshot `organizationUpdated`
+- Task realtime was already aligned to `taskUpdated`
+
+## Known blocker
+
+Spec item `3` is only partially done. The singleton constraint for the Better Auth `user` table is still blocked.
+
+- File: [foundry/packages/backend/src/actors/user/db/schema.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/user/db/schema.ts)
+- Reason: Better Auth still depends on external string `user.id`, so a literal singleton `CHECK (id = 1)` on that table is not a safe mechanical change.
+
+## Important current state
+
+There are uncommitted edits on top of the pushed checkpoint. Another agent should start from the current worktree, not just `origin/columbus-v2`.
+
+Current dirty files:
+
+- [foundry/packages/backend/src/actors/github-data/index.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/github-data/index.ts)
+- [foundry/packages/backend/src/actors/organization/actions.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/organization/actions.ts)
+- [foundry/packages/backend/src/actors/repository/actions.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/repository/actions.ts)
+- [foundry/packages/backend/src/actors/task/workspace.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/task/workspace.ts)
+- [foundry/packages/client/src/mock/backend-client.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/client/src/mock/backend-client.ts)
+
+These files are the current hot path for the unfinished structural work.
+
+## What is partially in place but not finished
+
+### User-owned task UI state
+
+The user actor already has the schema and CRUD surface for per-user task/session UI state:
+
+- [foundry/packages/backend/src/actors/user/db/schema.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/user/db/schema.ts)
+  `user_task_state`
+- [foundry/packages/backend/src/actors/user/index.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/user/index.ts)
+  `getTaskState`, `upsertTaskState`, `deleteTaskState`
+
+But the task actor and UI are still reading/writing the old task-global fields:
+
+- [foundry/packages/backend/src/actors/task/db/schema.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/task/db/schema.ts)
+  still contains `task_runtime.active_session_id` and session `unread` / `draft_*`
+- [foundry/packages/backend/src/actors/task/workspace.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/task/workspace.ts)
+  still derives unread/draft/active-session from task-local rows
+- [foundry/packages/frontend/src/components/mock-layout.tsx](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/frontend/src/components/mock-layout.tsx)
+  still treats `activeSessionId` as frontend-local and uses task-level unread/draft state
+
+So items `21`, `22`, `24`, and part of `19` are only half-done.
+
+### Coordinator ownership
+
+The current architecture still violates the intended coordinator pattern:
+
+- Organization still owns `taskLookup` and `taskSummaries`
+  - [foundry/packages/backend/src/actors/organization/db/schema.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/organization/db/schema.ts)
+- Organization still resolves `taskId -> repoId`
+  - [foundry/packages/backend/src/actors/organization/actions.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/organization/actions.ts)
+- Task still pushes summary updates to organization instead of repository
+  - [foundry/packages/backend/src/actors/task/workspace.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/task/workspace.ts)
+- Repository still does not own a `tasks` projection table yet
+  - [foundry/packages/backend/src/actors/repository/db/schema.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/repository/db/schema.ts)
+
+So items `9`, `13`, and `15` are still open.
+
+### Queue-only mutations
+
+Task actor workspace commands already go through queue sends. Other actors still do not fully follow the queue-only mutation rule:
+
+- [foundry/packages/backend/src/actors/user/index.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/user/index.ts)
+- [foundry/packages/backend/src/actors/github-data/index.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/github-data/index.ts)
+- [foundry/packages/backend/src/actors/organization/actions.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/organization/actions.ts)
+- [foundry/packages/backend/src/actors/organization/app-shell.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/organization/app-shell.ts)
+
+So items `4`, `10`, and `11` are still open.
+
+### Dynamic model/agent data
+
+The frontend/client still hardcode model groups:
+
+- [foundry/packages/frontend/src/components/mock-layout/view-model.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/frontend/src/components/mock-layout/view-model.ts)
+- [foundry/packages/client/src/workspace-model.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/client/src/workspace-model.ts)
+- [foundry/packages/shared/src/workspace.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/shared/src/workspace.ts)
+  `WorkspaceModelId` is still a hardcoded union
+
+The repo already has the API source of truth available through the TypeScript SDK:
+
+- [sdks/typescript/src/client.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/sdks/typescript/src/client.ts)
+  `SandboxAgent.listAgents({ config: true })`
+- [server/packages/sandbox-agent/src/router.rs](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/server/packages/sandbox-agent/src/router.rs)
+  `/v1/agents`
+- [server/packages/sandbox-agent/src/router/support.rs](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/server/packages/sandbox-agent/src/router/support.rs)
+  `fallback_config_options`
+
+So item `8` is still open.
+
+### GitHub sync chunking/progress
+
+GitHub data sync is still a delete-and-replace flow:
+
+- [foundry/packages/backend/src/actors/github-data/index.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/github-data/index.ts)
+  `replaceRepositories`, `replaceBranches`, `replaceMembers`, `replacePullRequests`, and full-sync flow
+- [foundry/packages/backend/src/actors/github-data/db/schema.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/github-data/db/schema.ts)
+  no generation/progress columns yet
+- [foundry/packages/shared/src/app-shell.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/shared/src/app-shell.ts)
+  no structured sync progress field yet
+
+So item `16` is still open.
+
+## Recommended next order
+
+If another agent picks this up, this is the safest order:
+
+1. Finish items `21`, `22`, `24`, `19` together.
+   Reason: user-owned task UI state is already half-wired, and task schema cleanup depends on the same files.
+
+2. Finish items `9`, `13`, `15` together.
+   Reason: coordinator ownership, repo-owned task projections, and PR/task unification are the same refactor seam.
+
+3. Finish item `16`.
+   Reason: GitHub sync chunking is mostly isolated to `github-data` plus app-shell/shared snapshot wiring.
+
+4. Finish item `8`.
+   Reason: dynamic model/agent data is largely independent once user default model is already user-scoped.
+
+5. Finish items `4`, `10`, `11`, `12`, `18`, final event audit.
+
+6. Do item `17` last.
+
+## Concrete file hotspots for the next agent
+
+Backend:
+
+- [foundry/packages/backend/src/actors/task/workspace.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/task/workspace.ts)
+- [foundry/packages/backend/src/actors/task/db/schema.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/task/db/schema.ts)
+- [foundry/packages/backend/src/actors/task/workflow/common.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/task/workflow/common.ts)
+- [foundry/packages/backend/src/actors/task/workflow/commands.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/task/workflow/commands.ts)
+- [foundry/packages/backend/src/actors/task/workflow/init.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/task/workflow/init.ts)
+- [foundry/packages/backend/src/actors/repository/actions.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/repository/actions.ts)
+- [foundry/packages/backend/src/actors/repository/db/schema.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/repository/db/schema.ts)
+- [foundry/packages/backend/src/actors/organization/actions.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/organization/actions.ts)
+- [foundry/packages/backend/src/actors/github-data/index.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/github-data/index.ts)
+- [foundry/packages/backend/src/actors/user/index.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/backend/src/actors/user/index.ts)
+
+Shared/client/frontend:
+
+- [foundry/packages/shared/src/workspace.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/shared/src/workspace.ts)
+- [foundry/packages/shared/src/contracts.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/shared/src/contracts.ts)
+- [foundry/packages/shared/src/app-shell.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/shared/src/app-shell.ts)
+- [foundry/packages/client/src/backend-client.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/client/src/backend-client.ts)
+- [foundry/packages/client/src/workspace-model.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/client/src/workspace-model.ts)
+- [foundry/packages/frontend/src/components/mock-layout.tsx](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/frontend/src/components/mock-layout.tsx)
+- [foundry/packages/frontend/src/components/mock-layout/view-model.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/frontend/src/components/mock-layout/model-picker.tsx)
+- [foundry/packages/frontend/src/features/tasks/status.ts](/Users/nathan/conductor/workspaces/sandbox-agent/columbus-v1/foundry/packages/frontend/src/features/tasks/status.ts)
+
+## Notes that matter
+
+- The pushed checkpoint is useful, but it is not the full current state. There are uncommitted edits in the hot-path backend files listed above.
+- The current tree already contains a partially added `user_task_state` path. Do not duplicate that work; finish the migration by removing the old task-owned fields and rewiring readers/writers.
+- The current task actor still reads mutable fields from `c.state` such as `repoRemote`, `branchName`, `title`, `task`, `sandboxProviderId`, and `agentType`. That is part of item `19`.
+- The current frontend still synthesizes PR-only rows into fake tasks. That should go away as part of repo-owned task projection / PR unification.