chore: update GPT-5.2 references to GPT-5.4

Align runtime defaults, tests, docs, and generated artifacts with the newer GPT-5.4 baseline. Keep think-mode and prompt-routing expectations consistent after the model version bump.

src/shared/model-suggestion-retry.test.ts

@@ -70,7 +70,7 @@ describe("parseModelSuggestion", () => {
           data: {
             providerID: "openai",
             modelID: "gpt-5",
-            suggestions: ["gpt-5.2"],
+            suggestions: ["gpt-5.4"],
           },
         },
       }
@@ -82,7 +82,7 @@ describe("parseModelSuggestion", () => {
       expect(result).toEqual({
         providerID: "openai",
         modelID: "gpt-5",
-        suggestion: "gpt-5.2",
+        suggestion: "gpt-5.4",
       })
     })