feat: add Requesty as a model provider

Add Requesty (https://requesty.ai), an OpenAI-compatible LLM router, as a
model provider by mirroring the existing OpenRouter integration.

Backend:
- app/services/requesty_model_normalizer.py: normalizes Requesty's /v1/models
  catalogue, mapping its flat capability booleans (supports_tool_calling/
  supports_vision/supports_image_generation) and context_window field onto the
  shared normalized shape (Requesty differs from OpenRouter's architecture +
  supported_parameters + context_length layout)
- provider_registry.py: Requesty ProviderSpec (OpenAI-compatible, base URL
  https://router.requesty.ai/v1, REQUESTY_API_KEY bearer auth)
- model_connection_service.py: key verification + live model discovery
- quality_score.py: Requesty score entry
- unit tests mirroring the OpenRouter normalizer coverage

Frontend:
- Requesty provider icon + registration, metadata entry, and base-url hint

Signed-off-by: Thibault Jaigu <thibault.jaigu@gmail.com>

surfsense_web/components/icons/providers/index.ts

@@ -27,6 +27,7 @@ export { default as PerplexityIcon } from "./perplexity.svg";
 export { default as QwenIcon } from "./qwen.svg";
 export { default as RecraftIcon } from "./recraft.svg";
 export { default as ReplicateIcon } from "./replicate.svg";
+export { default as RequestyIcon } from "./requesty.svg";
 export { default as SambaNovaIcon } from "./sambanova.svg";
 export { default as TogetherAiIcon } from "./togetherai.svg";
 export { default as VertexAiIcon } from "./vertexai.svg";

surfsense_web/components/icons/providers/requesty.svg

@@ -0,0 +1 @@
+<svg fill="currentColor" fill-rule="evenodd" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M14.5 2a1 1 0 000 2h2.086l-5.293 5.293a1 1 0 001.414 1.414L18 5.414V7.5a1 1 0 102 0v-4.5a1 1 0 00-1-1h-4.5zM4 6a2 2 0 00-2 2v10a2 2 0 002 2h10a2 2 0 002-2v-4a1 1 0 10-2 0v4H4V8h4a1 1 0 000-2H4z"></path></svg>