perf(server): read only checkpoint capture baselines

apps/server/src/orchestration-v2/CheckpointCaptureService.test.ts

@@ -52,9 +52,13 @@ const modelSelection = {
 } as const;
 
 it.layer(layerProjectionStoreTest)("CheckpointCaptureServiceV2", (it) => {
-  it.effect.each([false, true])(
-    "captures without decoding history or losing newer delegated completion, ref lookup fails=%s",
-    (refLookupFails) =>
+  it.effect.each([
+    { ordinal: 1, refLookupFails: false },
+    { ordinal: 1, refLookupFails: true },
+    { ordinal: 128, refLookupFails: false },
+  ])(
+    "captures without decoding history or losing newer delegated completion, ordinal=$ordinal, ref lookup fails=$refLookupFails",
+    ({ ordinal, refLookupFails }) =>
       Effect.gen(function* () {
         const projectionStore = yield* ProjectionStore.ProjectionStoreV2;
         const now = yield* DateTime.now;
@@ -77,7 +81,7 @@ it.layer(layerProjectionStoreTest)("CheckpointCaptureServiceV2", (it) => {
         const staleRun: OrchestrationV2Run = {
           id: runId,
           threadId,
-          ordinal: 1,
+          ordinal,
           providerInstanceId,
           modelSelection,
           providerThreadId,
@@ -160,8 +164,8 @@ it.layer(layerProjectionStoreTest)("CheckpointCaptureServiceV2", (it) => {
           runId,
           nodeId: rootNodeId,
           parentCheckpointId: readyBaseline.id,
-          ordinalWithinScope: 1,
-          appRunOrdinal: 1,
+          ordinalWithinScope: ordinal,
+          appRunOrdinal: ordinal,
           ref: CheckpointRef.make("checkpoint-ref:captured-1"),
           status: "ready" as const,
           files: [],
@@ -251,6 +255,25 @@ it.layer(layerProjectionStoreTest)("CheckpointCaptureServiceV2", (it) => {
           payload: readyBaseline,
         });
         const sql = yield* SqlClient.SqlClient;
+        if (ordinal > 1) {
+          yield* sql`WITH RECURSIVE history(ordinal) AS (
+            SELECT 1 UNION ALL SELECT ordinal + 1 FROM history WHERE ordinal < ${ordinal - 1}
+          )
+          INSERT INTO orchestration_v2_projection_checkpoints
+            (checkpoint_id, thread_id, scope_id, node_id, ordinal_within_scope, status,
+              captured_at, payload_json)
+          SELECT 'checkpoint:history:' || ordinal, ${threadId}, ${scopeId}, ${rootNodeId},
+            ordinal, 'ready', ${DateTime.formatIso(now)}, '{}' FROM history`;
+        }
+        const baselineContext = yield* projectionStore.getCheckpointCaptureContext(
+          threadId,
+          { runId, scopeId },
+          { preservedCheckpoints: "baselines" },
+        );
+        assert.deepEqual(
+          [...baselineContext.preservedCheckpointOrdinals].toSorted((a, b) => a - b),
+          ordinal === 1 ? [0] : [0, ordinal - 1],
+        );
         yield* sql`INSERT OR REPLACE INTO orchestration_v2_projection_turn_items
           (turn_item_id, thread_id, run_id, node_id, provider_thread_id, provider_turn_id,
             parent_item_id, ordinal, type, status, updated_at, payload_json)

apps/server/src/orchestration-v2/CheckpointCaptureService.ts

@@ -66,7 +66,9 @@ export const layer: Layer.Layer<
       readonly scopeId: CheckpointScopeId;
     }) {
       const { run, rootNode, scope, providerThread, preservedCheckpointOrdinals, sideChat } =
-        yield* projections.getCheckpointCaptureContext(input.threadId, input);
+        yield* projections.getCheckpointCaptureContext(input.threadId, input, {
+          preservedCheckpoints: "baselines",
+        });
       // Stopped runs remain terminal; their checkpoint is the next message's rollback point.
       const stopped = run?.status === "interrupted" || run?.status === "cancelled";
 

apps/server/src/orchestration-v2/ProjectionStore.ts

@@ -748,6 +748,7 @@ export interface ProjectionStoreV2Shape {
   readonly getCheckpointCaptureContext: (
     threadId: ThreadId,
     target: { readonly runId: RunId; readonly scopeId: CheckpointScopeId },
+    options?: { readonly preservedCheckpoints: "baselines" },
   ) => Effect.Effect<ProjectionCheckpointCaptureContext, ProjectionStoreV2Error>;
   readonly getCheckpointRollbackContext: (
     threadId: ThreadId,
@@ -5962,6 +5963,7 @@ export const layer: Layer.Layer<ProjectionStoreV2, never, SqlClient.SqlClient> =
     const getCheckpointCaptureContext: ProjectionStoreV2Shape["getCheckpointCaptureContext"] = (
       threadId,
       target,
+      options,
     ) =>
       sql
         .withTransaction(
@@ -5992,7 +5994,12 @@ export const layer: Layer.Layer<ProjectionStoreV2, never, SqlClient.SqlClient> =
               sql<{ readonly ordinal: number }>`SELECT ordinal_within_scope AS ordinal
             FROM orchestration_v2_projection_checkpoints
             WHERE thread_id = ${threadId} AND scope_id = ${target.scopeId}
-              AND (status = 'ready' OR (status = 'missing' AND run_id IS NOT NULL))`,
+              AND (status = 'ready' OR (status = 'missing' AND run_id IS NOT NULL))
+              ${
+                options?.preservedCheckpoints === "baselines"
+                  ? sql`AND ordinal_within_scope IN (0, ${run === undefined ? null : Math.max(0, run.ordinal - 1)})`
+                  : sql``
+              }`,
             ]);
             return {
               run,