bump claude-opus alias to 4-7

anthropic shipped claude-opus-4-7 today; opencode also republished it.
point the "claude-opus" alias at the new version for both providers so
existing users get the upgrade automatically. openrouter hasn't
published 4.7 yet, so leave openRouterResolve at 4.6 as the BYOR fallback.

also clarify the latest-model snapshot comment: new model drops usually
just mean bumping the `resolve` on an existing alias, not adding a new one.

Made-with: Cursor

test/__snapshots__/models.test.ts.snap

@@ -3,8 +3,8 @@
 exports[`latest model per provider snapshot > matches snapshot 1`] = `
 {
   "anthropic": {
-    "modelId": "claude-sonnet-4-6",
-    "releaseDate": "2026-02-17",
+    "modelId": "claude-opus-4-7",
+    "releaseDate": "2026-04-16",
   },
   "deepseek": {
     "modelId": "deepseek-reasoner",
@@ -23,8 +23,8 @@ exports[`latest model per provider snapshot > matches snapshot 1`] = `
     "releaseDate": "2026-03-17",
   },
   "opencode": {
-    "modelId": "glm-5.1",
-    "releaseDate": "2026-04-07",
+    "modelId": "claude-opus-4-7",
+    "releaseDate": "2026-04-16",
   },
   "openrouter": {
     "modelId": "openrouter/elephant-alpha",

test/models.test.ts

@@ -164,8 +164,10 @@ describe("latest model per provider snapshot", async () => {
     }
   }
 
-  // when this fails, a provider shipped a new model. check whether we need
-  // to add or update an alias in models.ts before updating the snapshot.
+  // when this fails, a provider shipped a new model. usually that just means
+  // bumping the `resolve` on an existing alias in models.ts (e.g. point
+  // "claude-opus" at the latest opus) rather than introducing a new alias.
+  // refresh the alias resolution first, then update this snapshot.
   it("matches snapshot", () => {
     expect(latestByProvider).toMatchSnapshot();
   });