fix: list and open sessions across project directories

Sessions outside the server's launch directory were invisible and returned
404 on open, leaving the model picker empty. List without the SDK's
process-cwd filter and normalize working directories at the API boundary and
when reading stored session data, tolerating separator/normalization
differences (including Windows backslash vs forward slash). Requires Pi
coding agent SDK 0.78.0 or newer.

src/server/sessions/piSessionService.ts

@@ -25,6 +25,7 @@ import type { AuthChange } from "./authService.js";
 import { fallbackSessionName, generateShortSessionName } from "./sessionNameGenerator.js";
 import { computeEditPreview, type EditPreviewResult } from "./editPreview.js";
 import { createPiSessionManagerGateway } from "./piSessionManagerGateway.js";
+import { cwdPathsEqual } from "../workingDirectory.js";
 import type { WorkspaceActivityService } from "../activity/workspaceActivityService.js";
 
 function noop(): void {
@@ -44,7 +45,7 @@ function isPiSessionRef(ref: PiSessionLookup): ref is PiSessionRef {
 }
 
 function lookupMatchesActiveSession(ref: PiSessionLookup, active: ActiveSession<PiSessionRuntime>): boolean {
-  return !isPiSessionRef(ref) || active.runtime.cwd === ref.cwd;
+  return !isPiSessionRef(ref) || cwdPathsEqual(active.runtime.cwd, ref.cwd);
 }
 
 type QueuedPromptKind = "steer" | "followUp";