feat(web-sdk): add LLMProvider, STTProvider, TTSProvider interfaces to core

Typed interfaces give the compiler something to check against when
providers register or consumers call getProvider. Previously these
shapes were declared inline as anonymous types inside VoicePipeline,
which meant any mismatch was silent at runtime.

Author: sakirr

sdk/runanywhere-web/packages/core/src/Infrastructure/ProviderTypes.ts

@@ -0,0 +1,99 @@
+/**
+ * Typed provider interfaces for cross-package communication.
+ *
+ * Backend packages (@runanywhere/web-llamacpp, @runanywhere/web-onnx) implement
+ * these interfaces and register instances via `ExtensionPoint.registerProvider()`.
+ * Core code (e.g. VoicePipeline) retrieves them at runtime via
+ * `ExtensionPoint.getProvider()` with full compile-time type safety.
+ *
+ * Replaces the previous implicit `globalThis.__runanywhere_*` contract.
+ * See: https://github.com/RunanywhereAI/runanywhere-sdks/issues/371
+ */
+
+// ---------------------------------------------------------------------------
+// Provider Capability Keys
+// ---------------------------------------------------------------------------
+
+/**
+ * Typed capability keys for the provider registry.
+ * Each key maps to exactly one provider interface.
+ */
+export type ProviderCapability = 'llm' | 'stt' | 'tts';
+
+// ---------------------------------------------------------------------------
+// Provider Interfaces
+// ---------------------------------------------------------------------------
+
+/**
+ * LLM (text generation) provider — implemented by @runanywhere/web-llamacpp.
+ *
+ * Only the subset of the TextGeneration API that cross-package consumers
+ * (e.g. VoicePipeline) depend on. Backend packages may expose additional
+ * methods beyond this interface.
+ */
+export interface LLMProvider {
+  generateStream(
+    prompt: string,
+    options?: {
+      maxTokens?: number;
+      temperature?: number;
+      systemPrompt?: string;
+    },
+  ): Promise<{
+    stream: AsyncIterable<string>;
+    result: Promise<{
+      text: string;
+      tokensUsed: number;
+      tokensPerSecond: number;
+      [key: string]: unknown;
+    }>;
+    cancel: () => void;
+  }>;
+}
+
+/**
+ * STT (speech-to-text) provider — implemented by @runanywhere/web-onnx.
+ *
+ * Only the subset of the STT API that cross-package consumers depend on.
+ */
+export interface STTProvider {
+  transcribe(
+    audio: Float32Array,
+    options?: { sampleRate?: number },
+  ): Promise<{
+    text: string;
+    [key: string]: unknown;
+  }>;
+}
+
+/**
+ * TTS (text-to-speech) provider — implemented by @runanywhere/web-onnx.
+ *
+ * Only the subset of the TTS API that cross-package consumers depend on.
+ */
+export interface TTSProvider {
+  synthesize(
+    text: string,
+    options?: { speed?: number },
+  ): Promise<{
+    audioData: Float32Array;
+    sampleRate: number;
+    durationMs: number;
+    processingTimeMs: number;
+    [key: string]: unknown;
+  }>;
+}
+
+// ---------------------------------------------------------------------------
+// Provider Type Map (capability key → interface)
+// ---------------------------------------------------------------------------
+
+/**
+ * Maps each `ProviderCapability` string to its corresponding interface.
+ * Used by `registerProvider` / `getProvider` for compile-time type safety.
+ */
+export interface ProviderMap {
+  llm: LLMProvider;
+  stt: STTProvider;
+  tts: TTSProvider;
+}