Revert VOX preset to the NetTTS approximation

The tuned values (pitch 0, rate 15, head size 34, lowering 50) matched
the reference metrics better but sound far off the game voice, so restore
the published NetTTS approximation: pitch 3, rate 17, prominences 22,
head size 52, lowering 40, volume 70. Also revert the test expectations,
the published default metadata, and the tuning notes in the docs; keep
tools/vox_compare.py for future experiments.

docs/NOTES.md

@@ -129,14 +129,10 @@ without them.
 - VOX mode is Flextalk-only. The wrapper enables it with `VESKSLOP_TTS_VOX=1`
   (`VESKSLOP_TTS_VOX_CLEAN=1` drops the stutter wrapper); word mode
   (`VESKSLOP_TTS_WORDS=1`) wins and skips VOX prosody.
-- Half-Life presets (`VESKSLOP_TTS_PRESET=vox|hev`) target Keith Bell only. VOX starts
-  from NetTTS `nettts_flextalk_vox_profile.reg` (pitch 3, rate 17, head 52, lowering 40)
-  and is tuned against the game's word assets from `suchipi/half-life-vox-console`:
-  shipped values are pitch 0, rate 15, prominences 22, head size 34, lowering 50,
-  volume 70. Measured on 38 words vs the game assets: F0 82.3 vs 82.3 Hz, duration
-  22.99 vs 23.36 s, >2 kHz share 0.0172 vs 0.0186 (old approximation: 87.5 Hz /
-  22.28 s / 0.0137). `tools/vox_compare.py` reproduces the comparison. `hev`
-  (pitch 15, rate 24) remains an unverified starting point - HL1 credits the suit
+- Half-Life presets (`VESKSLOP_TTS_PRESET=vox|hev`) target Keith Bell only. VOX values
+  come from NetTTS `nettts_flextalk_vox_profile.reg`: pitch 3, rate 17, prominences 22,
+  head size 52, volume 70 (factory: 27/33/17/46/100); `vox` also implies VOX prosody.
+  `hev` (pitch 15, rate 24) is an unverified starting point - HL1 credits the suit
   sounds to Kelly Bailey with no published settings.
 - Flextalk rate/pitch are applied as **vendor tags** (`\!R` = duration factor,
   `\!%` = pitch multiplier), never `-s`/`-p`, because ITTSAttributes override the