Bind the existing fsspeech_* wrappers into the ui.Briefing, ui.CommandBriefing,
ui.Debriefing, and ui.TechRoom scripting sections so Lua UIs (e.g. SCPUI, which
overrides the native screens) can drive synthesized speech again.
Each section gets playTextToSpeech, stopTextToSpeech, pauseTextToSpeech,
isTextToSpeechPlaying, and isTextToSpeechEnabled. Briefing/command-brief/debrief
use FSSPEECH_FROM_BRIEFING; the tech room uses FSSPEECH_FROM_TECHROOM. fsspeech_play
already self-gates on the Speech.* options, so these are no-ops when speech is off.
Mike Nelson
96d5182bb1