Opt-in isolated worktree so parallel implementers don't stomp the shared
tree, hydrated to config parity so a worker differs from the primary only
in LLM provider.
- Worktrees seam (interface) behind SessionManager; GitWorktrees shells git
via ProcessBuilder (non-zero exit -> WorktreeException), FakeWorktrees for
tests. No live git in unit tests.
- acquire() 5-arg overload provisions add -> overlayParity -> spawn(cwd=wt)
-> register, unwinding the worktree on any failure before registration.
4-arg overload and shared-tree behavior unchanged (backward compatible).
- release() removes the checkout but never deletes the branch (it holds the
worker's commits + PR, CB-302).
- overlayParity copies local config (.mcp.json, settings.local.json, .env/
.envrc) into the worktree; tracked ones get --skip-worktree so a worker
can never stage the parity overlay.
- WorkerSession gains nullable worktree/branch; BridgedConfig.Worker gains
parityOverlay (default list) + top-level worktreeRoot.
- bridge_spawn / POST /workers gain an optional worktree(+ticket) arg; the
worker view includes worktree/branch only when non-null.
Verify fixes on the delegated impl: strip trailing dashes in slug()
(^-+|-+$, was ^-+|^-+$); make FakeWorktrees.add a pure fn of the branch
(nonce already unique); MCP worktreeRequest treats blank/"false" string as
no-worktree, matching the REST builder.
162 tests, 0 failures.
Dai Ha
97ecc7136e