Slice: continue Memory from a historical commit on a new branch #262

Parent

Part of #259. Related: #260 and #261.

What to build

While inspecting a historical Memory commit in the PersonaBot DM, a Human chooses “Continue from here.” The Orchestrator creates a new native Git branch at that exact commit and immediately switches the Memory Repository to it. The previous branch and its commits remain available in the graph. The existing Orchestrator Session continues and its next file read sees the new branch's working tree.

The selected commit may be visible as accepted or pending; creating a branch does not itself confer accepted Memory status. Git branch creation, validation, acceptance, and error behavior remain distinct and visible.

Acceptance criteria

• “Continue from here” on a displayed historical commit creates a new local branch at that commit and switches the real repository; the old branch/ref remains intact and both histories appear in the graph.
• The requested branch name is validated using Git semantics; an existing or invalid name yields a clear Channel result without overwriting a ref or discarding work.
• The current Orchestrator Session id remains the same, and a subsequent native file read returns the historical content or a normal missing-file result.
• Creating from a pending raw commit does not silently mark it accepted; current branch, commit status, and repair state are reflected accurately.
• Restart/requery preserves branch refs, current branch, and durable accepted-commit provenance.
• Real-repository integration tests and a live LLM-backed DSH Human QA URL verify branch creation, old-branch preservation, and same-Session read. Save screenshots and stop for Human QA.

Blocked by

• Slice: switch an existing Memory branch in a live Orchestrator Session #261 — branch-aware Memory acceptance and clean existing-branch switching.