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/model-resolver.ts

@@ -3,6 +3,7 @@ import type { FallbackModelObject } from "./fallback-model-object"
 import { normalizeModel } from "./model-normalization"
 import { resolveModelPipeline } from "./model-resolution-pipeline"
 import { KNOWN_VARIANTS } from "./known-variants"
+import type { ConnectedProvidersAdapter } from "./connected-providers-cache"
 import * as connectedProvidersCache from "./connected-providers-cache"
 
 export type ModelResolutionInput = {
@@ -44,13 +45,14 @@ export function resolveModel(input: ModelResolutionInput): string | undefined {
 
 export function resolveModelWithFallback(
 	input: ExtendedModelResolutionInput,
+	connectedProvidersAdapter: ConnectedProvidersAdapter = connectedProvidersCache,
 ): ModelResolutionResult | undefined {
 	const { uiSelectedModel, userModel, userFallbackModels, categoryDefaultModel, fallbackChain, availableModels, systemDefaultModel } = input
 	const resolved = resolveModelPipeline({
 		intent: { uiSelectedModel, userModel, userFallbackModels, categoryDefaultModel },
 		constraints: { availableModels },
 		policy: { fallbackChain, systemDefaultModel },
-	}, connectedProvidersCache)
+	}, connectedProvidersAdapter)
 
 	if (!resolved) {
 		return undefined