fix(runtime): preserve graph input provenance

Generated-by: Codex

Author: me2seeks

packages/runtime/src/graph-mode.ts

@@ -15,6 +15,7 @@ export function renderGraphModePrompt(): string {
     'Stay available to the user across supervisor turns. Intervene only through the typed graph controls, and explain material supervision decisions.',
     'Before advancing dependencies or finishing, read the committed child result with agent_output like {"locator":"child_session_run","child_session_id":"<childSessionId>","run_id":"<currentRunId>","view":"result","max_bytes":32768}. Use result.resultRecordId when selecting a final committed record. Read runtime_events or view=all only for a narrow diagnostic question. Then select committed result ids with update_agent_graph.finish and synthesize those results for the user.',
     'When scheduling dependent work, pass each upstream result.resultRecordId in input_ids. The Runtime resolves those references into bounded, source-linked operator handoffs, so do not manually restate the child conclusion in the next instruction.',
+    'For a result selected by a finished earlier graph epoch, use selected_result_inputs with the exact source_graph_id and result_id returned by view_agent_graph. Keep input_ids for records in the current graph; historical inputs carry data lineage only and never reuse old operators or control state.',
     'You may continue directly when the request is small or a graph would add ceremony without useful decomposition.',
     '</orchestration_mode>',
   ].join('\n');

packages/runtime/src/stream-graph-coordinator.ts

@@ -1231,7 +1231,7 @@ export class AgentGraphCoordinator {
     }
     const page = await this.#input.epochStore.listAgentGraphEpochPage({
       rootSessionId,
-      beforeEpoch: beforeEpoch ?? current.epoch,
+      beforeEpoch: Math.min(beforeEpoch ?? current.epoch, current.epoch),
       limit: 1,
     });
     const selected: AgentGraphSelectedResultInput[] = [];

packages/runtime/src/stream-graph-schedule-reconcile.ts

@@ -197,6 +197,9 @@ export async function reconcileAgentGraphSchedule(
       snapshot.observation.projection.records.map((record) => [record.recordId, record]),
     );
     for (const [recordId, record] of snapshot.selectedResultRecords) {
+      if (committedRecords.has(recordId)) {
+        throw new Error(`Selected graph result id ${recordId} collides with the current graph`);
+      }
       committedRecords.set(recordId, record);
     }
     const deferredWork: AgentGraphScheduleDeferredWork[] = [];