test(model-alias-seed): expect canonical antigravity provider for the agy alias

Same #8013 realignment as this PR: `getModelInfo` resolves the stored `agy/…` alias
target to its canonical provider id `antigravity` (ALIAS_TO_PROVIDER_ID). The stored
alias STRING stays `agy/gemini-pro-agent`; only the resolved `provider` is now
`antigravity`, not `agy`. Test updated to match. 6/0.

tests/unit/model-alias-seed.test.ts

@@ -42,8 +42,10 @@ test("default model alias seed writes missing aliases and is idempotent", async
   assert.equal(aliases["gemini-3-flash-preview"], undefined);
 
   const routed = await sseModelService.getModelInfo("gemini-3.1-pro");
+  // The stored alias target is "agy/gemini-pro-agent", but getModelInfo canonicalizes
+  // the "agy" alias to its provider id "antigravity" (ALIAS_TO_PROVIDER_ID, #8013).
   assert.deepEqual(routed, {
-    provider: "agy",
+    provider: "antigravity",
     model: "gemini-pro-agent",
     extendedContext: false,
   });