docs(douanier): scrub internal codename from the public OpenAPI surface

The /docs + /openapi.json title read "Douanier — the audio sub-API…" and
/healthz returned service:"douanier" — internal codename leaking to consumers.

- FastAPI title → "Nech.PL Audio Intelligence API"; description rewritten to
  describe the engines (no "customs gate" framing).
- /healthz service → "nech-audio".
- Regenerated clients/openapi.json snapshot (info.title now clean; 13 paths,
  servers=api.nech.pl/audio/v1) — feeds the generated-client pipeline (#44).

Built + redeployed; verified at the edge: openapi.json info.title and healthz
both clean. "Douanier" now survives only as the internal repo/metric name.
67 tests green.

armada/api/app.py

@@ -25,11 +25,12 @@ from engines import grade as grade_eng    # VENDORED copy of the Foundry grader
 from engines import naming as naming_eng  # VENDORED copy of the Foundry namer (see engines/naming.py)
 
 app = FastAPI(
-    title="Douanier — the `audio` sub-API of the nech.pl platform",
+    title="Nech.PL Audio Intelligence API",
     version="0.1.0",
-    description="Customs gate over the fleet's audio-intelligence engines. Served "
-                "publicly at /audio/v1/...; the platform gateway does central auth + "
-                "metering and injects X-Tenant/X-Scopes. See SRE.md + DEPLOY.md.",
+    description="Stem-aware audio analysis — emotion, features, sample role, loop "
+                "grading, onsets/tempo, waveform & spectrogram, loudness, naming. "
+                "The `audio` API of the Nech.PL APIs platform, served at /audio/v1/...; "
+                "the gateway does central auth + metering (Bearer token).",
     # internal paths (gateway strips /audio/v1 and proxies here at root); root_path
     # makes /openapi.json + docs advertise the PUBLIC /audio/v1/... paths to clients.
     root_path=config.ROOT_PATH,
@@ -116,7 +117,7 @@ def require_auth(request: Request) -> auth.Principal:
 def healthz():
     ok, hint = ears.available()
     return {
-        "service": config.SERVICE,
+        "service": "nech-audio",
         "api": "audio",
         "version": config.VERSION,
         "status": "ok",

armada/api/clients/openapi.json

 {
   "openapi": "3.1.0",
   "info": {
-    "title": "Douanier \u2014 the `audio` sub-API of the nech.pl platform",
-    "description": "Customs gate over the fleet's audio-intelligence engines. Served publicly at /audio/v1/...; the platform gateway does central auth + metering and injects X-Tenant/X-Scopes. See SRE.md + DEPLOY.md.",
-    "version": "0.1.0",
-    "x-engines": "emotion features samples grade onsets waveform analyze loudness spectrum naming separate"
+    "title": "Nech.PL Audio Intelligence API",
+    "description": "Stem-aware audio analysis \u2014 emotion, features, sample role, loop grading, onsets/tempo, waveform & spectrogram, loudness, naming. The `audio` API of the Nech.PL APIs platform, served at /audio/v1/...; the gateway does central auth + metering (Bearer token).",
+    "version": "0.1.0"
   },
   "paths": {
     "/healthz": {
@@ -720,7 +719,7 @@
   "servers": [
     {
       "url": "https://api.nech.pl/audio/v1",
-      "description": "nech.pl platform \u2014 audio sub-API"
+      "description": "Nech.PL APIs gateway (public)"
     }
   ]
 }
\ No newline at end of file

armada/api/tests/test_smoke.py

@@ -27,7 +27,7 @@ def test_healthz_ok():
     r = client.get("/healthz")
     assert r.status_code == 200
     body = r.json()
-    assert body["service"] == "douanier" and body["api"] == "audio"
+    assert body["service"] == "nech-audio" and body["api"] == "audio"
     assert "emotion" in body["engines"] and "separate" in body["engines"]