feat(kanban): resume runs' chat via Refine + isolate the event stream

Two intertwined changes that both touch the orchestrator hook + run console:

Isolate the agent event stream (perf):
- useRunStream owns the SSE stream + event log locally inside AgentRunBar, so a
  burst of streamed events re-renders only the console — never the board page or
  card modal (which was causing frame drops at run start).
- useOrchestrator is now a registry only; lifecycle events reflect back up via
  stable patchRun/reflectBevy reflectors (effect deps depend on those, not the
  whole object, avoiding a stream-teardown loop).

Session resume for Refine:
- Runs now persist their pi session (drop --no-session); each fresh run captures
  its session JSONL path into a new agent_runs.session_file column (additive,
  idempotent migration).
- Refine resumes the prior run's actual session (--session <path> → appends) in
  that run's own worktree (inherited, never owned), sending the operator's
  feedback as the next message in the same conversation with full prior context.
- owns_worktree guards remove()/cleanup so a refinement never destroys the
  owning run's worktree; bad refinement targets return 409.
- AgentRunBar shows Refine only for settled runs with a recorded session.
EOF && echo "" && git log --oneline -3

apps/docs/src/lib/orchestratorApi.ts

@@ -17,8 +17,12 @@ export interface AgentRun {
   cardId: string;
   status: RunStatus;
   useWorktree: boolean;
+  /** Whether this run created (and therefore owns/cleans up) its worktree. */
+  ownsWorktree: boolean;
   branch: string | null;
   worktreePath: string | null;
+  /** pi session JSONL path persisted for this run (resumable by refinements). */
+  sessionFile: string | null;
   prompt: string;
   summary: string | null;
   commitSha: string | null;
@@ -78,6 +82,11 @@ export interface StartRunInput {
   prompt?: string;
   useWorktree?: boolean;
   cleanupOnFinish?: boolean;
+  /**
+   * If set, start a refinement run that continues this prior run's branch with
+   * `prompt` as the operator's refinement feedback.
+   */
+  refineRunId?: string;
 }
 
 /** A commit on a run's branch that is not yet on main. */