bugfix(audiomanager): Fix dummy audio manager implementation for failing audio length script conditions in headless mode

[Caball009]

• Closes Incomplete implementation of dummy audio manager can cause mismatches in headless mode #2295
• Follow up for [ZH] Implement Headless Mode #651

Our current implementation of dummy audio manager is incomplete, because it cannot return the actual length of audio files. Replays will mismatch if they contain scripts that rely on this.

TODO:

• Make sure the Github CI can access the audio files.
• Replicate in Generals.

[greptile-apps]

Greptile Summary

This PR fixes a replay CRC mismatch in headless mode by replacing the stub AudioManagerDummy (which returned a hardcoded -1 for getFileLengthMS) with a new MilesAudioManagerDummy that inherits from MilesAudioManager. By not overriding openDevice(), closeDevice(), or getDevice(), the new dummy class lets the parent populate m_digitalHandle, which allows the inherited MilesAudioManager::getFileLengthMS() to open real audio streams and return accurate durations.\n\nThe companion change refactors the createAudioManager() and createRadar() factory methods across both Generals/ and GeneralsMD/ to accept a Bool dummy parameter, moving the dummy/real branching out of GameEngine::init() and into the concrete factory implementations in Win32GameEngine.h.\n\n- AudioManagerDummy removed from the shared Core/GameEngine/Include/Common/GameAudio.h header\n- MilesAudioManagerDummy added to MilesAudioManager.h, inheriting from MilesAudioManager\n- getFileLengthMS uses m_digitalHandle directly (not getDevice()), so the commented-out getDevice() override does not affect correctness\n- Factory signatures updated consistently across both game directories\n- Outstanding TODO: CI audio file access needs to be verified before this fix is fully validated

Confidence Score: 4/5

PR is on a clear path to merge; core logic is correct and all prior review concerns are resolved

The key fix — inheriting openDevice() from MilesAudioManager so that m_digitalHandle is populated and getFileLengthMS() can open real streams — is architecturally sound. getFileLengthMS accesses m_digitalHandle directly (confirmed in source), so neither the removed getDevice() override nor the empty selectProvider() override affects its correctness. All previously flagged issues are addressed. Score stays at 4 rather than 5 only because the PR's own TODO acknowledges that CI audio file access is not yet verified.

Core/GameEngineDevice/Include/MilesAudioDevice/MilesAudioManager.h — the new MilesAudioManagerDummy class

Important Files Changed

Filename	Overview
Core/GameEngineDevice/Include/MilesAudioDevice/MilesAudioManager.h	Core change: adds MilesAudioManagerDummy inheriting MilesAudioManager so openDevice() populates m_digitalHandle, enabling inherited getFileLengthMS() to function correctly; all audio playback methods overridden to no-ops
Core/GameEngine/Include/Common/GameAudio.h	Removes the old AudioManagerDummy stub class entirely; no other changes
Generals/Code/GameEngineDevice/Include/Win32Device/Common/Win32GameEngine.h	Updates createAudioManager() and createRadar() to accept Bool dummy and inline the conditional allocation
GeneralsMD/Code/GameEngineDevice/Include/Win32Device/Common/Win32GameEngine.h	Mirror of Generals change: updates createAudioManager() and createRadar() with Bool dummy parameter
Generals/Code/GameEngine/Source/Common/GameEngine.cpp	Replaces inline ternary allocation with createAudioManager(m_headless) and createRadar(m_headless) calls
GeneralsMD/Code/GameEngine/Source/Common/GameEngine.cpp	Same as Generals GameEngine.cpp: delegates headless branching to factory methods
Generals/Code/GameEngine/Include/Common/GameEngine.h	Updates pure virtual declarations of createRadar and createAudioManager to accept Bool dummy
GeneralsMD/Code/GameEngine/Include/Common/GameEngine.h	Mirror of Generals GameEngine.h: updates pure virtual declarations for createRadar and createAudioManager

_{Reviews (5): Last reviewed commit: "Replicated in Generals." | Re-trigger Greptile}

[greptile-apps]

_{5 files reviewed, 6 comments}

_{Edit Code Review Agent Settings | Greptile}

[Caball009]

Addressed feedback.

[Caball009]

Replicated in Generals.