fix(runs): count a model run once when the terminal node carries its result on

A terminal node's result is the record it received, so after post_upgrade the run
listed the same post-upgrade check twice and counted its cost twice (run view, run
list and model costs). Identical calls now count once.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/domain/workflow-model-calls.test.ts

@@ -27,4 +27,18 @@ describe('workflowModelCalls', () => {
     expect(calls[2]).toMatchObject({ instanceId: 'run-1', workflowId: 'update-radarr', summary: 'Clean start.', actions: ['hl ps'], at: '2026-09-22T21:35:00.000Z' });
     expect(totalCostUsd(calls)).toBeCloseTo(0.82);
   });
+
+  it('counts a model run once when a later node carries its result on, as the terminal node does', () => {
+    const postUpgrade = { action: 'model.postUpgrade', state: 'completed', report: { outcome: 'nothing_to_do', summary: 'Clean start.', actions: ['hl ps'], model: 'sonnet', costUsd: 0.2 } };
+    const notes = { verdict: 'attention', summary: 'A migration runs.', model: 'opus', costUsd: 0.12 };
+    const calls = workflowModelCalls({ id: 'run-1', workflowId: 'update-radarr' }, [
+      attempt(1, 'release_notes', notes),
+      attempt(2, 'gate', notes),
+      attempt(3, 'post_upgrade', postUpgrade),
+      attempt(4, 'terminal_updated', postUpgrade),
+    ]);
+
+    expect(calls.map((call) => call.nodeId)).toEqual(['release_notes', 'post_upgrade']);
+    expect(totalCostUsd(calls)).toBeCloseTo(0.32);
+  });
 });

src/domain/workflow-model-calls.ts

@@ -22,9 +22,19 @@ const cost = (value: unknown): number => (typeof value === 'number' && Number.is
 /**
  * The model runs a workflow run made, read from its node attempts: a model action's result carries `report`
  * (app/privileged-action-executor-adapter), the release notes operation's result carries `verdict` and `model`.
+ * A node that passes the record on (a terminal node's result is its input) repeats that result; the same call counts once.
  */
 export function workflowModelCalls(instance: { readonly id: string; readonly workflowId: string }, attempts: readonly NodeAttempt[]): WorkflowModelCall[] {
-  return attempts.flatMap((attempt): WorkflowModelCall[] => {
+  const seen = new Set<string>();
+  return attempts.flatMap((attempt) => modelCallOf(instance, attempt)).filter(({ nodeId: _nodeId, at: _at, ...call }) => {
+    const key = JSON.stringify(call);
+    if (seen.has(key)) return false;
+    seen.add(key);
+    return true;
+  });
+}
+
+function modelCallOf(instance: { readonly id: string; readonly workflowId: string }, attempt: NodeAttempt): WorkflowModelCall[] {
   const result = record(attempt.result);
   const at = attempt.finishedAt ?? attempt.startedAt;
   const base = { instanceId: instance.id, workflowId: instance.workflowId, nodeId: attempt.nodeId, at };
@@ -47,7 +57,6 @@ export function workflowModelCalls(instance: { readonly id: string; readonly wor
     }];
   }
   return [];
-  });
 }
 
 export function totalCostUsd(calls: readonly WorkflowModelCall[]): number {