fix(server): remove deleted custom models

apps/server/src/provider/Layers/ProviderRegistry.test.ts

@@ -600,6 +600,53 @@ it.layer(Layer.mergeAll(NodeServices.layer, ServerSettingsModule.layerTest(), Te
         ]);
       });
 
+      it("retains discovered models but never removed custom models", () => {
+        const discoveredModel = {
+          slug: "gpt-5.6-sol",
+          name: "GPT-5.6-Sol",
+          isCustom: false,
+          capabilities: null,
+        } as const;
+        const previousProvider = {
+          instanceId: ProviderInstanceId.make("codex"),
+          driver: ProviderDriverKind.make("codex"),
+          status: "ready",
+          enabled: true,
+          installed: true,
+          auth: { status: "authenticated" },
+          checkedAt: "2026-08-02T10:00:00.000Z",
+          version: "0.146.0",
+          models: [
+            discoveredModel,
+            {
+              slug: "removed-custom-model",
+              name: "removed-custom-model",
+              isCustom: true,
+              capabilities: null,
+            },
+          ],
+          slashCommands: [],
+          skills: [],
+        } as const satisfies ServerProvider;
+        const successfulRefresh = {
+          ...previousProvider,
+          checkedAt: "2026-08-02T10:01:00.000Z",
+          models: [discoveredModel],
+        } satisfies ServerProvider;
+        const incompleteRefresh = {
+          ...previousProvider,
+          checkedAt: "2026-08-02T10:02:00.000Z",
+          models: [],
+        } satisfies ServerProvider;
+
+        assert.deepStrictEqual(mergeProviderSnapshot(previousProvider, successfulRefresh).models, [
+          discoveredModel,
+        ]);
+        assert.deepStrictEqual(mergeProviderSnapshot(previousProvider, incompleteRefresh).models, [
+          discoveredModel,
+        ]);
+      });
+
       it("drops stale OpenCode models missing from a successful refresh", () => {
         const previousProvider = {
           instanceId: ProviderInstanceId.make("opencode"),

apps/server/src/provider/Layers/ProviderRegistry.ts

@@ -101,9 +101,10 @@ const mergeProviderModels = (
   nextModels: ReadonlyArray<ServerProvider["models"][number]>,
 ): ReadonlyArray<ServerProvider["models"][number]> => {
   const shouldRetainMissingModels = shouldRetainMissingProviderModels(provider);
+  const retainablePreviousModels = previousModels.filter((model) => !model.isCustom);
 
-  if (shouldRetainMissingModels && nextModels.length === 0 && previousModels.length > 0) {
-    return previousModels;
+  if (shouldRetainMissingModels && nextModels.length === 0 && retainablePreviousModels.length > 0) {
+    return retainablePreviousModels;
   }
 
   const previousBySlug = new Map(previousModels.map((model) => [model.slug, model] as const));
@@ -119,7 +120,7 @@ const mergeProviderModels = (
   });
   const nextSlugs = new Set(nextModels.map((model) => model.slug));
   return shouldRetainMissingModels
-    ? [...mergedModels, ...previousModels.filter((model) => !nextSlugs.has(model.slug))]
+    ? [...mergedModels, ...retainablePreviousModels.filter((model) => !nextSlugs.has(model.slug))]
     : mergedModels;
 };
 

apps/server/src/provider/providerStatusCache.test.ts

@@ -182,6 +182,51 @@ it.layer(NodeServices.layer)("providerStatusCache", (it) => {
     );
   });
 
+  it("uses current settings as the authority for cached custom models", () => {
+    const configuredCustomModel = {
+      slug: "configured-custom-model",
+      name: "configured-custom-model",
+      isCustom: true,
+      capabilities: emptyCapabilities,
+    } as const;
+    const cachedCodex = makeProvider(CODEX_DRIVER, {
+      models: [
+        configuredCustomModel,
+        {
+          slug: "removed-custom-model",
+          name: "removed-custom-model",
+          isCustom: true,
+          capabilities: emptyCapabilities,
+        },
+        {
+          slug: "gpt-5-mini",
+          name: "GPT-5 Mini",
+          isCustom: false,
+          capabilities: emptyCapabilities,
+        },
+      ],
+    });
+    const fallbackCodex = makeProvider(CODEX_DRIVER, {
+      models: [configuredCustomModel],
+    });
+
+    assert.deepStrictEqual(
+      hydrateCachedProvider({
+        cachedProvider: cachedCodex,
+        fallbackProvider: fallbackCodex,
+      }).models,
+      [
+        configuredCustomModel,
+        {
+          slug: "gpt-5-mini",
+          name: "GPT-5 Mini",
+          isCustom: false,
+          capabilities: emptyCapabilities,
+        },
+      ],
+    );
+  });
+
   it("ignores stale cached enabled state when the provider is now disabled", () => {
     const cachedCodex = makeProvider(CODEX_DRIVER, {
       checkedAt: "2026-04-10T12:00:00.000Z",

apps/server/src/provider/providerStatusCache.ts

@@ -21,7 +21,10 @@ const mergeProviderModels = (
   cachedModels: ReadonlyArray<ServerProvider["models"][number]>,
 ): ReadonlyArray<ServerProvider["models"][number]> => {
   const fallbackSlugs = new Set(fallbackModels.map((model) => model.slug));
-  return [...fallbackModels, ...cachedModels.filter((model) => !fallbackSlugs.has(model.slug))];
+  return [
+    ...fallbackModels,
+    ...cachedModels.filter((model) => !model.isCustom && !fallbackSlugs.has(model.slug)),
+  ];
 };
 
 export const orderProviderSnapshots = (