feat: in-app Orchestrator (Phase 2) — multi-agent conductor

Brings the deterministic Han-flow conductor into BooCode: launch any read-only
flow from BooChat or BooCoder, watch each agent stream live in a Paseo-style
run pane, get an evidence-disciplined report — on local Qwen, persisted and
resumable. Read-only enforced hard via qwen --approval-mode plan (orchestrator
tasks fail closed if qwen is unavailable; never fall to write-capable native).

Backend (apps/coder): re-homed conductor defs, flow_runs/flow_steps schema,
flow-runner + dispatcher onTaskTerminal hook, restart-resume, runs routes
(launch/list/get/cancel), user-channel WS. Contracts: two flow_run_* frames.
Web: orchestrator pane kind + OrchestratorPane, Workflow button + slash flows
(BooChat/BooCoder parity), FlowLauncherDialog, "New Orchestrator" in the + and
split menus, runs history + export. Plan: openspec/changes/orchestrator.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/web/src/api/client.ts

@@ -25,6 +25,8 @@ import type {
   PermissionPrompt,
   AgentCommand,
   WorkspaceState,
+  FlowRunRow,
+  FlowStepRow,
 } from './types';
 
 // v2.6 Phase 1-UX §9b: chat-scoped agent-session rows. Returned by
@@ -483,6 +485,34 @@ export const api = {
       }),
   },
 
+  // Orchestrator run API — proxied to boocoder at /api/coder/runs/*.
+  runs: {
+    launch: (body: {
+      project_id: string;
+      flow_name: string;
+      band: 'small' | 'medium' | 'large';
+      input: { question: string };
+      model?: string;
+    }) =>
+      request<{ run_id: string }>('/api/coder/runs', {
+        method: 'POST',
+        body: JSON.stringify(body),
+      }),
+    list: (projectId: string) =>
+      request<{ runs: FlowRunRow[] }>(
+        `/api/coder/runs?project_id=${encodeURIComponent(projectId)}`,
+      ),
+    get: (runId: string) =>
+      request<{ run: FlowRunRow; steps: FlowStepRow[] }>(
+        `/api/coder/runs/${encodeURIComponent(runId)}`,
+      ),
+    cancel: (runId: string) =>
+      request<{ cancelled: boolean }>(
+        `/api/coder/runs/${encodeURIComponent(runId)}/cancel`,
+        { method: 'POST' },
+      ),
+  },
+
   agents: {
     list: (projectId: string) =>
       request<AgentsResponse>(`/api/projects/${projectId}/agents`),