feat(playground): image & video generation tabs + real chat metrics

The infosave collection now ships media models (Lumina-Image-2.0, MiniMax-H3
Turbo) that cortiq runs via `imagine`/`animate` CLI, not `cortiq serve`. The
gateway grows a media API: local .cmf files are classified by `cortiq info`
(chat/image/video, cached), generations run as tracked jobs with step progress
parsed from stdout, one at a time, cancellable, outputs under <data>/media.

The playground becomes three tabs. Image: width/height/steps/CFG/seed, live
progress, result rendered from P6 PPM to a canvas in the browser (PNG export
via toBlob). Video: frames/steps/quality/seed plus optional first/last
keyframes (rasterized to PPM client-side); the MJPEG+PCM AVI is decoded in JS
and played on a canvas synced to the wav — no ffmpeg on either side (mp4 remux
happens opportunistically when ffmpeg exists). A metrics card shows resolution,
steps, seed, total time, time per step/frame and file size.

Chat metrics: the local cortiq server sends no usage chunk in streams, so
token counts showed 0/0. tap_stream now injects one OpenAI-shaped usage event
ahead of [DONE] with the gateway's ~4-chars/token estimate, flagged
`cortiq_estimated`; the UI renders it as "≈ N / M" and adds tok/s and
time-to-first-token. Registration skips media packs (a `cortiq serve` entry
for a diffusion model would only fail) in both Register and the wizard's
Finish.

36 new UI strings translated across all 7 languages.

web/js/i18n/es.js

@@ -468,4 +468,42 @@ export default {
   "onboarding.deleteFile": "Eliminar el archivo .cmf del disco",
   "onboarding.confirmDelete": "¿Eliminar «{id}»? El archivo .cmf se borrará del disco.",
   "onboarding.unregistered": "También se dio de baja: {ids}",
+
+  // playground: media generation + streaming metrics
+  "pg.tab.chat": "Chat",
+  "pg.tab.image": "Imagen",
+  "pg.tab.video": "Vídeo",
+  "pg.generate": "Generar",
+  "pg.generating": "Generando…",
+  "pg.genFailed": "La generación falló — revisa el registro.",
+  "pg.result": "Resultado",
+  "pg.genMetrics": "Métricas de generación",
+  "pg.imagePromptPlaceholder": "un zorro rojo en la nieve al atardecer, fotorrealista, pelaje detallado",
+  "pg.videoPromptPlaceholder": "un corgi con gorro de chef voltea una tortita, chisporroteo y un ladrido alegre",
+  "pg.imageEmpty": "La imagen generada aparecerá aquí.",
+  "pg.videoEmpty": "El clip generado (con audio) aparecerá aquí.",
+  "pg.width": "Ancho",
+  "pg.height": "Alto",
+  "pg.steps": "Pasos",
+  "pg.seed": "Seed",
+  "pg.randomSeed": "Seed aleatorio",
+  "pg.cfgHint": "Escala de guidance; ≤ 1 desactiva el CFG y reduce el trabajo a la mitad.",
+  "pg.frames": "Fotogramas",
+  "pg.framesHint": "A 24 fps; se ajusta a la rejilla del modelo.",
+  "pg.quality": "Calidad JPEG",
+  "pg.videoSizeHint": "Múltiplos de 32; el lado corto entrenado es 768.",
+  "pg.videoStepsHint": "La LoRA Turbo está entrenada para 4 pasos.",
+  "pg.firstFrame": "Primer fotograma (opcional)",
+  "pg.lastFrame": "Último fotograma (opcional)",
+  "pg.keyframeHint": "Convierte la ejecución en keyframe-to-video.",
+  "pg.resolution": "Resolución",
+  "pg.genTime": "Tiempo de generación",
+  "pg.timePerStep": "Por paso",
+  "pg.timePerFrame": "Por fotograma",
+  "pg.fileSize": "Tamaño del archivo",
+  "pg.duration": "Duración",
+  "pg.play": "Reproducir",
+  "pg.noMediaModels": "Aún no hay un modelo {kind} local. Descarga uno (p. ej. de la colección infosave) en Importar:",
+  "pg.tokSpeed": "Velocidad",
+  "pg.ttft": "Primer token",
 };