refactor(model-core): remove src back-imports via core utilities and adapter

- move fuzzyMatchModel and transformModelForProvider into model-core

- replace connected-providers re-export with adapter contract

- route shared wrappers through model-core exports

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

packages/model-core/src/connected-providers-cache.ts

@@ -1,5 +1,38 @@
-export {
-  findProviderModelMetadata,
-  readConnectedProvidersCache,
-  readProviderModelsCache,
-} from "../../../src/shared/connected-providers-cache"
+import type { ModelMetadata } from "./provider-cache"
+
+export interface ProviderModelsCache {
+	readonly models: Record<string, readonly string[] | readonly ModelMetadata[]>
+	readonly connected: readonly string[]
+	readonly updatedAt: string
+}
+
+export interface ConnectedProvidersAdapter {
+	readConnectedProvidersCache(): string[] | null
+	findProviderModelMetadata(providerID: string, modelID: string): ModelMetadata | undefined
+	readProviderModelsCache(): ProviderModelsCache | null
+}
+
+export function readConnectedProvidersCache(): string[] | null {
+	return null
+}
+
+export function findProviderModelMetadata(
+	_providerID: string,
+	_modelID: string,
+): ModelMetadata | undefined {
+	return undefined
+}
+
+export function readProviderModelsCache(): ProviderModelsCache | null {
+	return null
+}
+
+export const connectedProvidersAdapter: ConnectedProvidersAdapter = {
+	readConnectedProvidersCache,
+	findProviderModelMetadata,
+	readProviderModelsCache,
+}
+
+export const disconnectedConnectedProvidersAdapter: ConnectedProvidersAdapter = {
+	...connectedProvidersAdapter,
+}