test(sessions): resolve POSIX fixture paths that are drive-relative on Windows

Five tests failed only on the Windows runner. Their fixtures used bare
POSIX-absolute paths such as /srv/other-worktree and /old-project, which
win32 treats as absolute but drive-relative: resolve() maps them onto the
runner's current drive (D:\...). The code under test canonicalizes stored
cwds by contract, so assertions comparing against the raw fixture string
never matched on Windows:

- parentSessionLocator and crossWorkspace listings annotate
  parentSessionCwd with canonicalizeStoredCwd(header.cwd);
- cleanup forgets unread via canonicalizeStoredCwd(record.cwd), which
  missed the marker the test seeded with the raw path.

Resolve the fixture paths once at declaration, matching the existing
WORKSPACE_CWD = resolve("/workspace") convention, so fixtures model what
a real Windows Pi would record. Linux behavior is unchanged.

src/server/sessions/parentSessionLocator.test.ts

@@ -1,10 +1,13 @@
+import { resolve } from "node:path";
 import { describe, expect, it, vi } from "vitest";
 import { countOutOfListingChildren, locateOutOfListingParents } from "./parentSessionLocator.js";
 import type { SessionHeaderSummary } from "./sessionFileHeader.js";
 
 const PARENT_PATH = "/sessions/--srv-other--/parent.jsonl";
 const LISTING_CWD = "/srv/dev/pi-web";
-const PARENT_CWD = "/srv/other-worktree";
+// Resolved because the locator canonicalizes header cwds: a bare "/srv/..." is
+// drive-relative on Windows and would land on the runner's current drive.
+const PARENT_CWD = resolve("/srv/other-worktree");
 
 describe("locateOutOfListingParents", () => {
   it("reports the cwd and id of a parent that is not in the listing", async () => {

src/server/sessions/piSessionService.crossWorkspace.test.ts

@@ -1,13 +1,16 @@
 import { mkdtemp, rm, writeFile } from "node:fs/promises";
 import { tmpdir } from "node:os";
-import { join } from "node:path";
+import { join, resolve } from "node:path";
 import { afterEach, beforeEach, describe, expect, it } from "vitest";
 import { PiSessionService, type PiSessionListEntry } from "./piSessionService.js";
 import { CapturingSessionEventHub, emptyArchiveStore, fakeSessionManager, sessionRecord, testModelRuntime, type SessionGateway } from "./piSessionService.testSupport.js";
 
 const TEST_AGENT_DIR = "/tmp/pi-web-test-agent";
 const CHILD_CWD = "/srv/dev/pi-web";
-const PARENT_CWD = "/srv/dev/pi-web-feature";
+// Resolved because the service canonicalizes header cwds before annotating: a
+// bare "/srv/..." is drive-relative on Windows and would land on the runner's
+// current drive.
+const PARENT_CWD = resolve("/srv/dev/pi-web-feature");
 
 let tempDir: string;
 

src/server/sessions/piSessionService.unread.test.ts

@@ -694,9 +694,13 @@ describe("PiSessionService daemon-owned unread state", () => {
 
   it("clears unread for sessions archived and deleted by cleanup", async () => {
     const unreadStore = new SessionUnreadStore({ createCatalogId: () => "catalog-test" });
-    completeStoreWork(unreadStore, "cleanup-archive", "/old-project");
-    completeStoreWork(unreadStore, "cleanup-delete", "/old-project");
-    const archivedRecord = { sessionId: "cleanup-delete", cwd: "/old-project", archivedAt: "2026-04-01T00:00:00.000Z", archivePath: "/archive/cleanup-delete.jsonl" };
+    // Resolved because the service canonicalizes cwds before forgetting unread:
+    // a bare "/old-project" is drive-relative on Windows and would land on the
+    // runner's current drive, so the seeded marker would never match.
+    const oldProjectCwd = resolve("/old-project");
+    completeStoreWork(unreadStore, "cleanup-archive", oldProjectCwd);
+    completeStoreWork(unreadStore, "cleanup-delete", oldProjectCwd);
+    const archivedRecord = { sessionId: "cleanup-delete", cwd: oldProjectCwd, archivedAt: "2026-04-01T00:00:00.000Z", archivePath: "/archive/cleanup-delete.jsonl" };
     const service = new PiSessionService(new CapturingSessionEventHub(), {
       agentDir: TEST_AGENT_DIR,
       modelRuntime: testModelRuntime,
@@ -705,7 +709,7 @@ describe("PiSessionService daemon-owned unread state", () => {
       sessionManager: {
         create: () => fakeSessionManager(),
         list: () => Promise.resolve([]),
-        listAll: () => Promise.resolve([sessionRecord("cleanup-archive", "/old-project")]),
+        listAll: () => Promise.resolve([sessionRecord("cleanup-archive", oldProjectCwd)]),
         open: () => fakeSessionManager(),
       },
       archiveStore: {