fix(server): remove abandoned v1 database copies on startup

apps/server/src/persistence/initializeV2Database.test.ts

@@ -1,4 +1,5 @@
 // @effect-diagnostics nodeBuiltinImport:off
+import * as NodeChildProcess from "node:child_process";
 import * as NodeFS from "node:fs";
 import * as NodeOS from "node:os";
 import * as NodePath from "node:path";
@@ -182,3 +183,28 @@ it.effect("starts fresh without V1 and never imports over existing V2 state", ()
     Effect.ensuring(Effect.sync(() => NodeFS.rmSync(directory, { recursive: true, force: true }))),
   );
 });
+
+it.effect("removes copies left by a killed start, but not one that is still running", () => {
+  const directory = NodeFS.mkdtempSync(NodePath.join(NodeOS.tmpdir(), "t3-v2-abandoned-"));
+  const killed = NodeChildProcess.spawnSync(process.execPath, ["-e", ""]).pid;
+  const running = `.v2-import-${process.pid}-Kq81Zx`;
+  const unrelated = ".v2-import-not-a-copy";
+  return Effect.gen(function* () {
+    for (const name of [`.v2-import-${killed}-Wm3nPa`, ".v2-import-Q3xZ9a", running]) {
+      NodeFS.mkdirSync(NodePath.join(directory, name));
+      NodeFS.writeFileSync(NodePath.join(directory, name, "snapshot.sqlite"), "partial copy");
+    }
+    NodeFS.mkdirSync(NodePath.join(directory, unrelated));
+    const destinationPath = NodePath.join(directory, "statev2.sqlite");
+    NodeFS.writeFileSync(destinationPath, "existing V2 database");
+    yield* initializeV2Database(destinationPath);
+    assert.deepEqual(
+      NodeFS.readdirSync(directory).sort(),
+      [running, unrelated, "statev2.sqlite"].sort(),
+    );
+    assert.equal(NodeFS.readFileSync(destinationPath, "utf8"), "existing V2 database");
+  }).pipe(
+    Effect.provide(NodeServices.layer),
+    Effect.ensuring(Effect.sync(() => NodeFS.rmSync(directory, { recursive: true, force: true }))),
+  );
+});

apps/server/src/persistence/initializeV2Database.ts

@@ -14,6 +14,33 @@ export class V2DatabaseImportError extends Schema.TaggedError<V2DatabaseImportEr
   }
 }
 
+const isProcessAlive = (pid: number): boolean => {
+  if (!Number.isInteger(pid) || pid <= 0) return false;
+  try {
+    process.kill(pid, 0);
+    return true;
+  } catch (error) {
+    return error instanceof Error && "code" in error && error.code === "EPERM";
+  }
+};
+
+// Legacy names have no PID; newer copies stay while their process is alive.
+const removeAbandonedCopies = Effect.fn("removeAbandonedCopies")(function* (directory: string) {
+  const fs = yield* FileSystem.FileSystem;
+  const path = yield* Path.Path;
+  const entries = yield* fs.readDirectory(directory).pipe(
+    Effect.catchIf(
+      (error) => error.reason._tag === "NotFound",
+      () => Effect.succeed([]),
+    ),
+  );
+  for (const entry of entries) {
+    const copy = /^\.v2-import-(?:(\d+)-)?[A-Za-z0-9]{6}$/.exec(entry);
+    if (copy === null || (copy[1] !== undefined && isProcessAlive(Number(copy[1])))) continue;
+    yield* fs.remove(path.join(directory, entry), { recursive: true });
+  }
+});
+
 /** Its copied legacy tables remain the source for lazy transcript import. */
 export const initializeV2Database = Effect.fn("initializeV2Database")(function* (
   destinationPath: string,
@@ -22,12 +49,13 @@ export const initializeV2Database = Effect.fn("initializeV2Database")(function*
   const path = yield* Path.Path;
   const directory = path.dirname(destinationPath);
   const sourcePath = path.join(directory, "state.sqlite");
+  yield* removeAbandonedCopies(directory).pipe(Effect.ignore({ log: true }));
   yield* Effect.gen(function* () {
     if (yield* fs.exists(destinationPath)) return;
     if (!(yield* fs.exists(sourcePath))) return;
     const temporaryDirectory = yield* fs.makeTempDirectoryScoped({
       directory,
-      prefix: ".v2-import-",
+      prefix: `.v2-import-${process.pid}-`,
     });
     const snapshotPath = path.join(temporaryDirectory, "snapshot.sqlite");
     yield* Effect.tryPromise(async () => {