catalog(fish-s2): drop Imogen_Contralto (pitch-shift variants abandoned)

Pitch-shifted deepening (rubberband, formant on/off) sounded bad at every
depth (tuba / over-gravelly), so abandoned. Removed Imogen_Contralto from the
dropdown + deleted the staged variants (fish + chatterbox). Plain unmodified
Imogen remains. version 5->6.

docs/asset-engine/services.yaml

@@ -619,7 +619,7 @@ services:
       Trained 10M+ hours, dual-AR. Released March 2026. Heavy: ~240s compile
       warmup on cold start, ~realtime throughput once warm.
     category: tts
-    version: 5
+    version: 6
     host: irv-ml1
     lifecycle:
       stack: fish-s2
@@ -717,7 +717,6 @@ services:
           - Beatrice
           - Eleanor
           - Imogen
-          - Imogen_Contralto
           - Connor
           - Cora
           - Elena
@@ -743,14 +742,12 @@ services:
           - Thomas
         description: >
           Voice = a staged clone reference picked by name (THE working voice
-          path on this build; verified live 2026-06-01). 33 voices staged in
+          path on this build; verified live 2026-06-01). 32 voices staged in
           /worktank/fish-s2/references/: 28 from the dia library + glados + 3
-          British-female VCTK voices (Beatrice/Eleanor/Imogen) + Imogen_Contralto.
-          Default Emily. Subtle British (Southern-England) female accents: Imogen
-          (VCTK p225), Eleanor (p228), Beatrice (p229) — consenting VCTK
-          volunteers (CC BY 4.0), NOT modeled on or representing any public
-          figure. Imogen_Contralto = Imogen pitch-shifted -3 semitones
-          (rubberband, formants follow) for a deeper contralto register. Other female:
+          British-female VCTK voices (Beatrice/Eleanor/Imogen). Default Emily.
+          Subtle British (Southern-England) female accents: Imogen (VCTK p225),
+          Eleanor (p228), Beatrice (p229) — consenting VCTK volunteers (CC BY
+          4.0), NOT modeled on or representing any public figure. Other female:
           Abigail, Alice, Cora, Elena, Emily, Gianna, Jade, Layla, Olivia,
           glados. Resolves to <name>.wav + optional <name>.txt transcript;
           blank = model default/random speaker. To add: drop a clean 5–15s WAV