refactor(shared): deduplicate model resolution utility functions

Extract normalizeModel() (3 identical copies) and normalizeModelID()
(2 identical copies) into canonical src/shared/model-normalization.ts.
Delete dead-end duplicate model-name-matcher.ts. Update all consumers.

src/hooks/anthropic-effort/hook.ts

@@ -1,11 +1,7 @@
-import { log } from "../../shared"
+import { log, normalizeModelID } from "../../shared"
 
 const OPUS_4_6_PATTERN = /claude-opus-4[-.]6/i
 
-function normalizeModelID(modelID: string): string {
-  return modelID.replace(/\.(\d+)/g, "-$1")
-}
-
 function isClaudeProvider(providerID: string, modelID: string): boolean {
   if (["anthropic", "google-vertex-anthropic", "opencode"].includes(providerID)) return true
   if (providerID === "github-copilot" && modelID.toLowerCase().includes("claude")) return true