Bug: --change-state CLI silently fails (calls non-existent method) #571

Description

The --change-state CLI command (added in #460) silently fails — it exits with code 0 but has no effect on the StreamDeck device.

Root Cause

on_change_state in src/app.py and the api_state_requests handler in src/backend/DeckManagement/DeckController.py both call gl.page_manager.get_best_page_path_match_from_name(), which does not exist on PageManagerBackend. The correct method is find_matching_page_path(), which on_change_page and the api_page_requests handler already use correctly.

The AttributeError is swallowed by GTK's D-Bus action handler, so there is no error output or log entry — the command just silently does nothing.

Steps to Reproduce

1. Set up a StreamDeck button with multiple states
2. Run: streamcontroller --change-state <SERIAL> <PAGE> <x,y> 1
3. Observe: command exits successfully, but button state does not change
4. Check logs: no on_change_state log entry appears

Expected Behavior

The button state should change on the physical device and in the UI, with a log entry like:

Successfully changed state of (x,y) to state 1 on device <SERIAL>

Environment

• StreamController installed via AUR (streamcontroller-git)
• Stream Deck Original
• Arch Linux

Fix

#570