Summary

Closes the "Launch as background service when game starts" item in the README to-do list. Adds three new CLI flags to main.py so users can run the RPC as a Windows tray service that auto-starts on login.

pip install pystray Pillow pylnk3
python main.py --tray              # foreground tray icon
python main.py --install-autostart # boot --tray on Windows login
python main.py --uninstall-autostart

The tray menu exposes Status (waiting / running / error), Open log file, Restart, and Quit. Quitting drains the watcher cleanly via a threading.Event.

What changed

main.py additions:

• module-level _stop_event = threading.Event()
• monitor_log()'s outer loop checks _stop_event and uses _stop_event.wait(5.0) instead of time.sleep(5) so Quit can interrupt within ~5s
• run_tray() — pystray icon + daemon worker thread + Quit/Restart/Open log handlers
• install_autostart() / uninstall_autostart() — pylnk3-backed shortcut at %APPDATA%/Microsoft/Windows/Start Menu/Programs/Startup
• argparse dispatch at the entry point: --tray, --install-autostart, --uninstall-autostart, --quiet

Optional dependencies

pystray, Pillow, and pylnk3 are imported lazily inside the helpers — python main.py (the existing flow) keeps working with zero new deps. If a user passes --tray or --install-autostart without the extras installed, they get a clear pip install ... hint and exit code 1.

requirements.txt documents the optional install as a comment so the runtime baseline (psutil, pypresence) is byte-identical.

Backwards compatibility

• No flag → identical behavior to current main.py (rpc_connect() + monitor_log())
• Existing call sites untouched; the only mutation to existing logic is time.sleep(5) → _stop_event.wait(5.0), which is functionally equivalent when no flags are set
• No new files added; no new required dependencies

Test plan

• Windows live-smoke: python main.py --tray, confirm menu shows, status flips waiting → running once a character logs in
• Windows live-smoke: python main.py --install-autostart creates %APPDATA%/.../Startup/PathOfExile2DiscordRPC.lnk; reboot; tray launches without console
• Windows live-smoke: python main.py --uninstall-autostart removes the shortcut and exits 0 (or 1 if the shortcut was absent)
• python main.py (no flags) behaves identically to before this PR
• python main.py --tray without pystray/Pillow exits 1 with the install hint
• python main.py --install-autostart without pylnk3 exits 1 with the install hint

Notes for review

• This is the 4th of 4 small, independent PRs; the others are Support official PoE2 client (PathOfExile.exe) alongside Steam build #6 (official PoE2 client), Detect local player & filter party-member level events (auto-pin via 'You have entered') #7 (owner detection), Reflect AFK/DND status in Rich Presence (small_image + [AFK] suffix) #8 (AFK status). They can land in any order.
• Tray uses pystray's recommended pattern: icon on the main thread (Windows requirement), worker on a daemon thread.
• Restart re-execs via os.execv(sys.executable, [sys.executable, *sys.argv]) so all flags are preserved.
• Happy to split this into PR-4a (autostart only, requires only pylnk3) and PR-4b (tray, requires pystray + Pillow) if growing the optional-deps surface in one shot is too much.