fix(server): drop V1 projections nothing reads after the V2 upgrade (pingdotgg#20947)

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

Author: juliusmarminge

apps/server/src/persistence/Migrations.ts

@@ -65,6 +65,7 @@ import Migration0059 from "./Migrations/059_McpAppModelContext.ts";
 import Migration0060 from "./Migrations/060_ThreadSnapshotWindowIndexes.ts";
 import Migration0061 from "./Migrations/061_PullRequestReviewGuides.ts";
 import Migration0062 from "./Migrations/062_ThreadFailureLookupIndex.ts";
+import Migration0063 from "./Migrations/063_DropUnusedV1Projections.ts";
 
 export const migrationEntries = [
   [1, "OrchestrationEvents", Migration0001],
@@ -130,6 +131,7 @@ export const migrationEntries = [
   [60, "ThreadSnapshotWindowIndexes", Migration0060],
   [61, "PullRequestReviewGuides", Migration0061],
   [62, "ThreadFailureLookupIndex", Migration0062],
+  [63, "DropUnusedV1Projections", Migration0063],
 ] as const;
 
 export const migrationManifest = migrationEntries.map(([id, name]) => [id, name] as const);

apps/server/src/persistence/Migrations/055_OrchestrationV2.test.ts

@@ -13,7 +13,7 @@ layer("055_OrchestrationV2", (it) => {
     Effect.sync(() => {
       assert.deepStrictEqual(
         migrationEntries.map(([id]) => id),
-        Array.from({ length: 62 }, (_, index) => index + 1),
+        Array.from({ length: 63 }, (_, index) => index + 1),
       );
     }),
   );
@@ -34,6 +34,7 @@ layer("055_OrchestrationV2", (it) => {
         [60, "ThreadSnapshotWindowIndexes"],
         [61, "PullRequestReviewGuides"],
         [62, "ThreadFailureLookupIndex"],
+        [63, "DropUnusedV1Projections"],
       ]);
       assert.deepStrictEqual(yield* runMigrations(), []);
 
@@ -62,6 +63,7 @@ layer("055_OrchestrationV2", (it) => {
         { migration_id: 60, name: "ThreadSnapshotWindowIndexes" },
         { migration_id: 61, name: "PullRequestReviewGuides" },
         { migration_id: 62, name: "ThreadFailureLookupIndex" },
+        { migration_id: 63, name: "DropUnusedV1Projections" },
       ]);
 
       const tables = yield* sql<{ readonly name: string }>`

apps/server/src/persistence/Migrations/063_DropUnusedV1Projections.test.ts

@@ -0,0 +1,49 @@
+import { assert, it } from "@effect/vitest";
+import * as NodeSqliteClient from "@t3tools/shared/nodeSqliteClient";
+import * as Effect from "effect/Effect";
+import * as SqlClient from "effect/sql/SqlClient";
+
+import { runMigrations } from "../Migrations.ts";
+
+const layer = it.layer(NodeSqliteClient.layer({ filename: ":memory:" }));
+
+layer("063_DropUnusedV1Projections", (it) => {
+  it.effect("drops V1 projections nothing reads and keeps the transcript import sources", () =>
+    Effect.gen(function* () {
+      const sql = yield* SqlClient.SqlClient;
+      yield* runMigrations({ toMigrationInclusive: 62 });
+      yield* sql`
+        INSERT INTO projection_thread_messages
+          (message_id, thread_id, role, text, is_streaming, created_at, updated_at)
+        VALUES ('message-1', 'thread-1', 'user', 'hello', 0, '2026-01-01', '2026-01-01')
+      `;
+
+      yield* runMigrations({ toMigrationInclusive: 63 });
+
+      const rows = yield* sql<{ readonly name: string }>`
+        SELECT name FROM sqlite_master WHERE type = 'table'
+      `;
+      const tables = new Set(rows.map((row) => row.name));
+      for (const dropped of [
+        "projection_thread_activities",
+        "projection_turns",
+        "projection_thread_proposed_plans",
+        "projection_pending_approvals",
+        "projection_state",
+        "checkpoint_diff_blobs",
+      ]) {
+        assert.isFalse(tables.has(dropped), dropped);
+      }
+      for (const kept of [
+        "projection_threads",
+        "projection_thread_messages",
+        "projection_thread_pull_requests",
+      ]) {
+        assert.isTrue(tables.has(kept), kept);
+      }
+      assert.deepEqual(yield* sql`SELECT message_id FROM projection_thread_messages`, [
+        { message_id: "message-1" },
+      ]);
+    }),
+  );
+});

apps/server/src/persistence/Migrations/063_DropUnusedV1Projections.ts

@@ -0,0 +1,20 @@
+import * as Effect from "effect/Effect";
+import * as SqlClient from "effect/sql/SqlClient";
+
+/**
+ * V2 databases start as a copy of the V1 database, and nothing reads these V1
+ * projections after the copy. The V1 transcript import still reads threads,
+ * messages and pull request links, so those stay. Builds before 0.1.0 read
+ * `state.sqlite`, never this file, so dropping them does not affect a rollback.
+ * The freed pages are reported as reclaimable space for `t3 doctor`.
+ */
+export default Effect.gen(function* () {
+  const sql = yield* SqlClient.SqlClient;
+
+  yield* sql`DROP TABLE IF EXISTS projection_thread_activities`;
+  yield* sql`DROP TABLE IF EXISTS projection_turns`;
+  yield* sql`DROP TABLE IF EXISTS projection_thread_proposed_plans`;
+  yield* sql`DROP TABLE IF EXISTS projection_pending_approvals`;
+  yield* sql`DROP TABLE IF EXISTS projection_state`;
+  yield* sql`DROP TABLE IF EXISTS checkpoint_diff_blobs`;
+});

apps/server/src/persistence/reconcileV2PreviewMigration.test.ts

@@ -42,6 +42,7 @@ describe("V2 preview upgrade", () => {
         [60, "ThreadSnapshotWindowIndexes"],
         [61, "PullRequestReviewGuides"],
         [62, "ThreadFailureLookupIndex"],
+        [63, "DropUnusedV1Projections"],
       ]);
       assert.deepStrictEqual(yield* runMigrations(), []);
       assert.deepStrictEqual(yield* sql`SELECT * FROM orchestration_v2_legacy_imports`, imports);
@@ -127,6 +128,7 @@ describe("V2 preview upgrade", () => {
         [60, "ThreadSnapshotWindowIndexes"],
         [61, "PullRequestReviewGuides"],
         [62, "ThreadFailureLookupIndex"],
+        [63, "DropUnusedV1Projections"],
       ]);
     }).pipe(Effect.provide(NodeSqliteClient.layer({ filename: ":memory:" }))),
   );

scripts/mobile-showcase-environment.ts

@@ -21,18 +21,6 @@ export const SHOWCASE_SCENES = [
 ] as const;
 export type ShowcaseScene = (typeof SHOWCASE_SCENES)[number];
 
-const PROJECTOR_NAMES = [
-  "projection.projects",
-  "projection.threads",
-  "projection.thread-messages",
-  "projection.thread-proposed-plans",
-  "projection.thread-activities",
-  "projection.thread-sessions",
-  "projection.thread-turns",
-  "projection.checkpoints",
-  "projection.pending-approvals",
-] as const;
-
 const MODEL_SELECTION = JSON.stringify({ instanceId: "codex", model: "gpt-5.4" });
 const PROJECT_SCRIPTS = JSON.stringify([
   {
@@ -392,23 +380,6 @@ function insertThread(
       snoozedUntil,
       snoozedAt,
     );
-  database
-    .prepare(
-      `INSERT INTO projection_turns (
-        thread_id, turn_id, pending_message_id, assistant_message_id, state, requested_at,
-        started_at, completed_at, checkpoint_turn_count, checkpoint_ref, checkpoint_status,
-        checkpoint_files_json, source_proposed_plan_thread_id, source_proposed_plan_id
-      ) VALUES (?, ?, NULL, ?, ?, ?, ?, ?, NULL, NULL, NULL, '[]', NULL, NULL)`,
-    )
-    .run(
-      input.id,
-      turnId,
-      isWorking ? null : `${input.id}-answer`,
-      isWorking ? "running" : "completed",
-      minutesBefore(now, input.minutesAgo + 2),
-      minutesBefore(now, input.minutesAgo + 2),
-      isWorking ? null : updatedAt,
-    );
   database
     .prepare(
       `INSERT INTO projection_thread_sessions (
@@ -424,14 +395,9 @@ function insertThread(
 // do not read the V1 thread rows; moving the seed to V2 is tracked in
 // https://github.com/pingdotgg/t3code/issues/15013.
 const SEEDED_V1_TABLES = [
-  "projection_pending_approvals",
-  "projection_thread_proposed_plans",
-  "projection_thread_activities",
   "projection_thread_messages",
   "projection_thread_sessions",
-  "projection_turns",
   "projection_threads",
-  "projection_state",
 ] as const;
 
 const SEEDED_PROJECTION_TABLES = [...SEEDED_V1_TABLES, "projection_projects"] as const;
@@ -558,62 +524,6 @@ function seedDatabase(
       }
     }
 
-    const turnId = `${SHOWCASE_THREAD_ID}-turn`;
-    const insertActivity = database.prepare(
-      `INSERT INTO projection_thread_activities (
-        activity_id, thread_id, turn_id, tone, kind, summary, payload_json, sequence, created_at
-      ) VALUES (?, ?, ?, 'tool', 'tool.completed', ?, ?, ?, ?)`,
-    );
-    insertActivity.run(
-      "trace-remote-handoff",
-      SHOWCASE_THREAD_ID,
-      turnId,
-      "Traced the remote handoff path",
-      JSON.stringify({
-        itemType: "command_execution",
-        title: "Traced the remote handoff path",
-        detail: "Three environments, one continuous workspace",
-        status: "completed",
-      }),
-      1,
-      minutesBefore(now, 8),
-    );
-    insertActivity.run(
-      "sync-command-center",
-      SHOWCASE_THREAD_ID,
-      turnId,
-      "Synced the command center",
-      JSON.stringify({
-        itemType: "file_change",
-        title: "Synced the command center",
-        detail: "2 files changed · instant handoffs · calm reconnects",
-        status: "completed",
-      }),
-      2,
-      minutesBefore(now, 6),
-    );
-    insertActivity.run(
-      "run-changed-suite",
-      SHOWCASE_THREAD_ID,
-      turnId,
-      "Ran the changed workspace",
-      JSON.stringify({
-        itemType: "command_execution",
-        title: "Ran the changed workspace",
-        detail: "612 tests passed · 3 environments online",
-        status: "completed",
-      }),
-      3,
-      minutesBefore(now, 4),
-    );
-
-    for (const [index, projector] of PROJECTOR_NAMES.entries()) {
-      database
-        .prepare(
-          "INSERT INTO projection_state (projector, last_applied_sequence, updated_at) VALUES (?, ?, ?)",
-        )
-        .run(projector, index + 1, minutesBefore(now, 1));
-    }
     database.exec("COMMIT");
   } catch (error) {
     // A failed BEGIN (or an error SQLite already auto-rolled back) leaves no