Implement a batch of tickets through per-ticket subagents

The manual loop was one /implement invocation per ticket, all of it
running in the session the human was talking to. This adds an
orchestration layer instead: the invoked agent plans and dispatches,
and every line of ticket code is written by a subagent in its own
git worktree.

.claude/skills/implement-tickets is the orchestrator — collect the
tickets over tea, group them into waves by their blocking edges (three
wide), fix the cross-ticket contracts up front, gate on the human's
approval, then dispatch a wave as one task batch and land it: merge,
comment, close, remove the worktree.

.omp/agents/ticket-implementer is the worker. It reads a brief, reads
the ticket and its parent for intent, runs the tdd skill at the seams
the brief names, commits, then gates itself on the two-axis review
through cr-spec and cr-standards before reporting a short status.

Agents are discovered from .omp/agents, never .claude/agents. Verified
by dispatch that the agent resolves and that it can spawn cr-spec —
the orchestrator/implementer/reviewer chain clears the recursion cap.

.gitignore

@@ -7,6 +7,7 @@ backend/backend
 .playwright-mcp/
 graphify-out/
 plans/
+.scratch/
 docs/superpowers/
 .superpowers/
 go.work