Add crunch presets, echo options, and streaming word mode

docs/voice.md

@@ -163,6 +163,16 @@ from the TTS panel:
   so the parser is skipped and the vendor tags go on every word (`\!R` rate, `\!%` pitch). VOX
   needs `python3` on the host. Both travel to the command provider as
   `VESKSLOP_TTS_VOX` / `VESKSLOP_TTS_VOX_CLEAN` (or the `{vox}` / `{vox_clean}` placeholders).
+  A **crunch** stage adds the lossy 1990s codec character as its own step **after** the rest of the
+  chain (echo tails included): `tts.crunch` presets `hl90` (8-bit, 11 kHz), `hl90hq` (8-bit,
+  22 kHz), `telephone` (8 kHz band-limited), `adpcm` (4-bit) and `crush` (custom), with optional
+  `tts.crunchBits` (1-16) and `tts.crunchRate` (4-48 kHz) overrides. The output stays 48 kHz
+  s16le, so only the character changes. Echo gained `tts.echoDelayMs` (10-400) and
+  `tts.echoLevel` (0-0.95) alongside the amount. **Stream word mode** (`tts.streamWords`, on by
+  default) makes the wrapper write the WAV while it synthesizes, so playback starts on the first
+  word: measured first sound 0.5 s instead of 2.4 s on a ten-word line. Streaming skips the
+  loudness measurement (`VESKSLOP_TTS_STREAM_GAIN_DB` compensates if needed) and cannot use VOX
+  prosody, which needs the whole sentence.
   A **preset** select (`tts.preset`: factory, VOX, HEV) shifts the Keith Bell speaker profile to
   the Half-Life approximation; `vox` also implies VOX prosody unless VOX is explicitly off, and
   overrides travel as `VESKSLOP_TTS_PRESET` / `{preset}`. Precedence is preset < profile <