revert: remove gpt-5.4-pro (structured outputs not supported)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: FL4TLiN3

packages/core/src/known-models/index.ts

@@ -110,13 +110,6 @@ export const knownModels = [
   {
     provider: "openai",
     models: [
-      // https://developers.openai.com/api/docs/models/gpt-5.4-pro
-      {
-        name: "gpt-5.4-pro",
-        tier: "high" as const,
-        contextWindow: 1_050_000,
-        maxOutputTokens: 128_000,
-      },
       // https://developers.openai.com/api/docs/models/gpt-5.4
       {
         name: "gpt-5.4",

packages/core/src/known-models/model-tiers.test.ts

@@ -27,7 +27,7 @@ describe("@perstack/core: resolveModelTier", () => {
   it("resolves openai tiers", () => {
     expect(resolveModelTier("openai", "low")).toBe("gpt-5-nano")
     expect(resolveModelTier("openai", "middle")).toBe("gpt-5-mini")
-    expect(resolveModelTier("openai", "high")).toBe("gpt-5.4-pro")
+    expect(resolveModelTier("openai", "high")).toBe("gpt-5.4")
   })
 
   it("resolves google tiers", () => {
@@ -48,7 +48,7 @@ describe("@perstack/core: resolveModelTier", () => {
   })
 
   it("falls back to base provider for cloud-hosted providers", () => {
-    expect(resolveModelTier("azure-openai", "high")).toBe("gpt-5.4-pro")
+    expect(resolveModelTier("azure-openai", "high")).toBe("gpt-5.4")
     expect(resolveModelTier("azure-openai", "middle")).toBe("gpt-5-mini")
     expect(resolveModelTier("azure-openai", "low")).toBe("gpt-5-nano")
     expect(resolveModelTier("amazon-bedrock", "high")).toBe("claude-opus-4-6")