improve reasoning toggle tests and refactor model capability checks

public/app/modelCapabilities.js

@@ -1,6 +1,12 @@
 // Conservative allowlist for models supporting the boolean think API.
 // Unknown models remain usable for normal chat.
-export function supportsReasoning(model) {
-    const id = String(typeof model === "string" ? model : model?.model || model?.name || "").toLowerCase().split("/").at(-1);
-    return /^(qwen3|deepseek-r1|deepseek-v3\.1)(:|$)/.test(id);
+const reasoningFamilies = new Set(["qwen3", "deepseek-r1", "deepseek-v3.1"]);
+
+export function getModelFamily(model) {
+    const id = typeof model === "string" ? model : model?.model || model?.name || model?.id || "";
+    return String(id).trim().toLowerCase().split("/").at(-1).split(":")[0];
+}
+
+export function supportsReasoning(model) {
+    return reasoningFamilies.has(getModelFamily(model));
 }