feat(workflows): M6 — dashboard run-history + DAG view

A per-app "Workflows" tab: list definitions, browse run history, and inspect a
run's per-step progress with a static layered DAG.

- API: the run-detail endpoint now returns each step's `depends_on` (loaded
  from the definition via a new `get_workflow_by_id` reader) so the dashboard
  can draw the graph edges — the run's step rows don't carry them.
- dashboard `$lib/api`: a `workflows` namespace (list / runs / start / run) +
  the matching types.
- `apps/[slug]/workflows/+page.svelte`: workflow table → drill into runs →
  drill into a run. The run view renders a step table plus an SVG DAG (nodes =
  steps colored by status, laid out by longest-path level; edges = depends_on,
  arrowed) and a "Start run" button. Nested/parked steps show their child run.
- AppTabBar + the per-app layout gain the Workflows tab (admin-only).

Tests: `npm run check` clean (0 errors); two Playwright smoke tests
(navigation tabs — workflows loads cleanly + renders its empty state) pass
against the full stack.

With M6 the v1.2 Workflows track (M1 schema/validation → M2 durable
orchestrator → M3 when/templating → M4 nested → M5 SDK/API/CLI → M6 dashboard)
is COMPLETE.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

dashboard/src/lib/api.ts

@@ -444,6 +444,57 @@ export interface CreateQueueTriggerInput {
 	retry_base_ms?: number;
 }
 
+// v1.2 Workflows — read/run types (admin workflows API).
+export interface WorkflowSummary {
+	name: string;
+	enabled: boolean;
+	steps: number;
+}
+
+export type WorkflowRunStatus =
+	| 'pending'
+	| 'running'
+	| 'succeeded'
+	| 'failed'
+	| 'canceled';
+
+export interface WorkflowRun {
+	id: string;
+	workflow_id?: string;
+	status: WorkflowRunStatus;
+	error?: string | null;
+	workflow_depth: number;
+	created_at: string;
+	input?: unknown;
+	output?: unknown;
+	started_at?: string | null;
+	finished_at?: string | null;
+}
+
+export type WorkflowStepStatus =
+	| 'pending'
+	| 'ready'
+	| 'running'
+	| 'succeeded'
+	| 'failed'
+	| 'skipped';
+
+export interface WorkflowRunStep {
+	name: string;
+	status: WorkflowStepStatus;
+	attempt: number;
+	max_attempts: number;
+	error?: string | null;
+	child_run_id?: string | null;
+	depends_on: string[];
+	output?: unknown;
+}
+
+export interface WorkflowRunDetail {
+	run: WorkflowRun;
+	steps: WorkflowRunStep[];
+}
+
 // v1.1.9 — read-only queue inspection types (admin queues API).
 export interface QueueSummary {
 	queue_name: string;
@@ -1214,6 +1265,26 @@ export const api = {
 			)
 	},
 
+	workflows: {
+		list: (idOrSlug: string) =>
+			adminRequest<WorkflowSummary[]>(
+				`/api/v1/admin/apps/${encodeURIComponent(idOrSlug)}/workflows`
+			),
+		runs: (idOrSlug: string, name: string) =>
+			adminRequest<WorkflowRun[]>(
+				`/api/v1/admin/apps/${encodeURIComponent(idOrSlug)}/workflows/${encodeURIComponent(name)}/runs`
+			),
+		start: (idOrSlug: string, name: string, input: unknown) =>
+			adminRequest<WorkflowRun>(
+				`/api/v1/admin/apps/${encodeURIComponent(idOrSlug)}/workflows/${encodeURIComponent(name)}/runs`,
+				{ method: 'POST', body: JSON.stringify({ input }) }
+			),
+		run: (idOrSlug: string, runId: string) =>
+			adminRequest<WorkflowRunDetail>(
+				`/api/v1/admin/apps/${encodeURIComponent(idOrSlug)}/workflow-runs/${encodeURIComponent(runId)}`
+			)
+	},
+
 	topics: {
 		list: (idOrSlug: string) =>
 			adminRequest<{ topics: Topic[] }>(