The previous talkie-overlay refactor lost the rest/active behaviour and
left the radio-shake CSS animation running constantly. Restore the
intended polish:
- Position lerp between TALKIE_REST_Y (idle) and TALKIE_ACTIVE_Y
(raised when narrator is speaking) with a subtle floating bob.
- Subtle z-axis float at idle, faster shake when active.
- Gate the CSS radio-shake on the new --active modifier so the talkie
is calm when no narrator dialogue is playing.
- Keep the face-camera rotation [0.18, PI, -0.08] from the original
overlay version.
Visibility still kicks in at the reveal step (no regression on the
recent fix).
Regression introduced by the narrator-video revert (1ad0c4d): the talkie
overlay was hidden whenever no narrator subtitle was active. Restore the
prior behaviour where the talkie stays visible from the reveal step
onward and only the --raised modifier and signal lines depend on the
active narrator dialogue.
Tom Boullay