PlayRemote Mac 2.7.3 - Startup reliability

This update registers the login agent immediately, preserves crash supervision
when a manually launched copy is already running, and retries temporary errors
while checking macOS permissions.

For an existing installation:
1. Choose Quit Play Remote in the old host. Do not delete its Keychain entry.
2. Extract this archive. Copy desktop.py, mac_support.py and updater.py from its
   PlayRemote2 folder into your EXISTING PlayRemote2 folder, replacing those files.
   Keep the existing .venv folder and the remaining files.
3. Open Start-PlayRemote.command from that existing folder.
4. Select Enable automatic remote access and check the status becomes ONLINE.
5. Connect from another device, then test again after 15 minutes idle.

For a new installation, extract the full folder to a permanent location, open
Start-PlayRemote.command, register the Mac and enable automatic remote access.
Python 3.12+ with Tk is required. Allow Screen Recording and Accessibility for
the actual host/Python in macOS Settings if prompted. A browser permission is
not a substitute for host permission. Do not move the installed folder later.

Automated startup-configuration and settings tests pass. End-to-end Mac testing
is still required; this release does not prove the reported offline issue fixed.
It does not bypass login/FileVault or wake a powered-off or manually sleeping Mac.
The signed automatic update channel remains 2.7.2 pending on-device validation.
