ACP: @deepseek-ai/dsh-acp does not implement session/load, so clients cannot restore conversation history

[ig505gi]

Problem

The ACP bridge (@deepseek-ai/dsh-acp) advertises sessionCapabilities: { close, list, resume } and implements session/resume — which by design resumes a session without replaying history. It does not implement the standard session/load method (resume + replay of prior turns as session/update notifications).

Reproduction

1. Connect an ACP client that uses session/load to restore a previous conversation (e.g. Paseo).
2. initialize → session/load { sessionId, cwd }
3. Server returns -32601 Method not found: session/load.

Impact

Clients that rely on session/load (e.g. Paseo, which rebuilds its UI timeline from the ACP replay) show an empty conversation after a client/daemon restart, even though the session log is intact. session/resume alone cannot fix this because it explicitly does not replay history.

Suggestion

Implement session/load in packages/acp: same checks as resumeSession, then replay the persisted history to the client as session/update notifications before responding, and advertise load: {} in sessionCapabilities.

Tested on @deepseek-ai/dsh-acp 0.1.5-rc.2; the latest dsh-v0.1.6-alpha.2 source has the same method set.