macOS desktop (0.9.0) does not restore session on launch — credentials persisted but not read #934

Environment

• App: PinePods native macOS desktop, Apple Silicon
• Version: 0.9.0 (build 20260626.143526)
• macOS: Tahoe 26.5.2, Apple Silicon
• Server: self-hosted

Description
After signing in and quitting the app (⌘Q), the app requires a full re-login on
next launch, including re-entering the server address.

Root cause (verified locally)
Credentials ARE persisted to disk but are never read back on startup. In
~/Library/Application Support/com.gooseberrydevelopment.pinepods/credentials/
three files are written correctly at login:

• userAuthState.json → server_name, username, api_key, password (all populated)
• serverState.json
• userState.json
  After ⌘Q and relaunch these files remain present and unchanged (verified via
  ls -la: identical size and mtime), yet the login screen reappears. So the
  saved session state is written but not loaded on startup.

Steps to reproduce

1. Launch app, sign in to a self-hosted server.
2. Quit with ⌘Q.
3. Relaunch → login screen, server address empty.
4. Inspect credentials/ folder → files still present with valid data.

Expected: Session is restored from userAuthState.json on launch.
Actual: Persisted credentials are ignored; re-login required every time.

Secondary bug (likely a serialization issue)
serverState.json contains a stray newline in the proxy config:
"proxy_host":"\n"
producing a malformed proxy_url:
"proxy_url":"://\n:/mover/?url="
The trailing "\n" looks like unstripped command output (hostname/container ID)
written into the config.