catalog(chatterbox-fast): add streaming TTS service entry (streamable:true)

Land chatterbox-fast in the asset-engine catalog as an additive service, per
asset-engine-dev's shipped streaming-audition path (asset-engine v0.1.17-19):
- streamable:true -> UI routes Generate to an ephemeral progressive-<audio>
  audition (no Job/Asset); re-run on `chatterbox` to keep output.
- New service-level `streamable` bool added to services.schema.json (additive,
  default false; mirrors the Pydantic model asset-engine-dev regenerates).
- Fields: text, voice (select via /voices), temperature/top_p/top_k/
  repetition_penalty/seed, format (pcm default; UI forces wav). exaggeration/
  cfg_weight omitted — Turbo ignores them.
- status experimental until the first real browser audition verifies progressive
  playback (the one thing asset-engine-dev couldn't machine-verify).
- reproducibility + audit entries added. No catalog_version bump (additive).
Validates against the updated schema.

docs/asset-engine/services.schema.json

@@ -589,6 +589,11 @@
           "title": "Content Type",
           "type": "string"
         },
+        "streamable": {
+          "default": false,
+          "title": "Streamable",
+          "type": "boolean"
+        },
         "model": {
           "$ref": "#/$defs/CatalogModel"
         },

docs/asset-engine/services.yaml

@@ -379,6 +379,132 @@ services:
       and deliberately NOT adopted. Python 3.10 only (wrapper hardcoding);
       multilingual (23-language) variant available via the stack .env.
 
+  - id: chatterbox-fast
+    name: Chatterbox Fast (streaming)
+    description: >
+      Custom streaming front-end for Chatterbox-Turbo: an adaptive buffer-ratchet
+      chunker emits the first sentence immediately (~0.5s time-to-first-audio vs
+      ~5s one-shot), then ratchets chunk size up on the model's realtime headroom.
+      Single-stream interactive. Same Turbo voice + inline paralinguistic tags as
+      `chatterbox`; the win is sub-second start for streaming consumers.
+    category: tts
+    version: 1
+    status: experimental
+    host: irv-ml1
+    lifecycle:
+      stack: chatterbox-fast
+      vram_gb: 6
+      gpu_device_id: 1
+    endpoint: http://10.100.79.3:8197/tts
+    method: POST
+    content_type: application/json
+    streamable: true
+    model:
+      id: ResembleAI/chatterbox-turbo
+      revision: null
+      image: local/chatterbox-fast:v1
+    section_groups:
+      - id: basic
+        label: Text & voice
+      - id: sampling
+        label: Sampling
+    fields:
+      - name: text
+        type: textarea
+        label: Text (with optional [tags])
+        section: basic
+        required: true
+        max_length: 5000
+        description: >
+          Inline paralinguistic tags honored by Turbo ([laugh] [whispers] [sigh]
+          etc.). Adaptive-chunking splits on sentence boundaries; a very long
+          comma-less sentence may show a faint join seam.
+      - name: voice
+        type: select
+        label: Voice
+        section: basic
+        default: glados_25s
+        source_url: http://10.100.79.3:8197/voices
+        source_jsonpath: $.voices[*]
+        description: >
+          Predefined voice (a *.wav stem under /worktank/chatterbox/reference_audio,
+          shared with the chatterbox stack). Live-enumerated via /voices. Clone
+          references are passable as an absolute path via the API (not listed here).
+      - name: temperature
+        type: slider
+        section: sampling
+        min: 0.05
+        max: 2.0
+        step: 0.05
+        default: 0.8
+        description: Sampling temperature; lower = steadier. Turbo default 0.8.
+      - name: top_p
+        type: slider
+        section: sampling
+        min: 0.0
+        max: 1.0
+        step: 0.05
+        default: 0.95
+        description: Nucleus sampling cutoff. Spike-validated default 0.95.
+      - name: top_k
+        type: number
+        section: sampling
+        required: false
+        default: 1000
+        description: Top-k sampling cutoff. Spike-validated default 1000.
+      - name: repetition_penalty
+        type: slider
+        section: sampling
+        min: 1.0
+        max: 2.0
+        step: 0.05
+        default: 1.2
+        description: Penalize token repetition. Spike-validated default 1.2.
+      - name: seed
+        type: number
+        section: sampling
+        required: false
+        default: 0
+        description: >
+          0 = random. A fixed seed repeats a one-shot take (verified byte-exact).
+          Streaming output is NOT reproducible — adaptive-chunk boundaries depend
+          on the live-measured realtime factor.
+      - name: format
+        type: select
+        section: basic
+        options: [pcm, wav]
+        default: pcm
+        description: >
+          pcm = raw s16le @ 24 kHz (lowest latency, for API consumers); wav adds a
+          header. The streaming-audition UI forces wav for the browser <audio>.
+    response:
+      type: audio
+      mime_from_field: format
+    reproducibility:
+      seedable: true
+      deterministic: false
+      seed_field: seed
+      notes: >
+        One-shot (non-streaming) output is reproducible for a fixed seed + params
+        (verified byte-identical 2026-06-02). STREAMING output is NOT — adaptive-
+        chunk boundaries depend on live-measured RTF (wall-clock), so splits vary
+        run to run; streamable auditions are ephemeral anyway (no Asset). PerTh
+        watermark is applied unconditionally (Resemble policy).
+    estimated_latency:
+      cold_start_s: 16
+      warm_per_unit: "~0.5s TTFB streaming, ~3.9× realtime (A6000)"
+    license: MIT
+    notes: |
+      Streaming front-end built in-house (eshpfi stacks/chatterbox-fast/): FastAPI
+      + ChatterboxTurboTTS + an adaptive buffer-ratchet scheduler. Deployed beside
+      the buffered `chatterbox` (:8196), which is unchanged. Defaults sourced from
+      the 2026-06-02 spike (temperature 0.8 / top_p 0.95 / top_k 1000 /
+      repetition_penalty 1.2). exaggeration / cfg_weight are deliberately omitted —
+      Turbo ignores them. streamable:true routes the UI to an ephemeral audition
+      (progressive <audio>, no Asset/library entry); re-run on `chatterbox` to keep
+      output. Status experimental until the first real browser audition verifies
+      progressive playback end-to-end.
+
   - id: index-tts
     name: IndexTTS-2
     description: >
@@ -2000,6 +2126,11 @@ reproducibility_audit:
     model_deterministic: false
     image_tag_mutable: true
     notes: "/tts exposes seed (0=random); temperature-sampled, not byte-exact. PerTh watermark unconditional (Resemble policy). image :latest is mutable — pin a digest/SHA for true repro."
+  - service: chatterbox-fast
+    seedable: true
+    model_deterministic: false
+    image_tag_mutable: true
+    notes: "/tts exposes seed (0=random) — one-shot byte-exact for fixed seed+params (verified 2026-06-02); STREAMING non-reproducible (timing-dependent chunk boundaries), auditions ephemeral. PerTh watermark unconditional. image local/chatterbox-fast:v1 is tag-pinned + mutable — pin a digest for true repro."
   - service: index-tts
     seedable: false
     model_deterministic: true