Minor UI fixes

e2e_tests/tests_omni_light/fixtures/modules.json

@@ -0,0 +1,19 @@
+{
+  "version": "1.0.0",
+  "includes": [{ "path": "modules_browser_only.json" }],
+  "modules": [
+    {
+      "id": "external-test-hello-world-route",
+      "type": "Routes",
+      "path": "@/modules/external-module-test/helloWorldRouteDefinition/create",
+      "dependencies": {}
+    },
+    {
+      "id": "routing-main",
+      "collisionStrategy": "merge",
+      "dependencies": {
+        "module:routes": ["external-test-hello-world-route"]
+      }
+    }
+  ]
+}

e2e_tests/tests_omni_light/scripts/run-frontend.sh

@@ -1,8 +1,9 @@
 #!/usr/bin/env bash
 # Builds and starts the Vite preview server for e2e light tests.
 #
-# Uses frontend/omni browser-only manifest and extends it at runtime with
-# external test module entries.
+# Uses frontend/omni browser-only manifest composed with the test fixtures
+# modules.json (which includes modules_browser_only.json and adds the external
+# test module entries via the composition system).
 
 set -euo pipefail
 
@@ -16,8 +17,7 @@ cd "$FRONTEND_DIR"
 rm -rf src/modules/external-module-test
 cp -R "$LIGHT_TESTS_DIR/fixtures/external-module-test" src/modules/external-module-test
 
-rm -f public/modules.json
-node "$LIGHT_TESTS_DIR/scripts/extend-light-modules-json.mjs"
+cp "$LIGHT_TESTS_DIR/fixtures/modules.json" public/modules.json
 
 pnpm install
 pnpm build

e2e_tests/tests_omni_light/src/chat.spec.ts

@@ -48,4 +48,26 @@ test.describe("Chat", () => {
         await chatPage.sendMessage("world");
         await chatPage.assertLastResponse("world");
     });
+
+    test("Each assistant message keeps the model that generated it", async ({
+        page,
+    }) => {
+        const chatPage = new ChatPage(page);
+
+        await chatPage.navigateTo();
+        await chatPage.selectModel("gpt-4o");
+
+        await chatPage.sendMessage("first message");
+        await chatPage.assertLastResponse("first message");
+        await chatPage.waitForIdle();
+
+        await chatPage.selectModel("gpt-4o-mini");
+
+        await chatPage.sendMessage("second message");
+        await chatPage.assertLastResponse("second message");
+        await chatPage.waitForIdle();
+
+        await chatPage.assertAssistantMessageModelName(0, "gpt-4o");
+        await chatPage.assertAssistantMessageModelName(1, "gpt-4o-mini");
+    });
 });

e2e_tests/tests_omni_light/src/pages.ts

@@ -44,28 +44,62 @@ export class ChatPage {
                 hasText: /Select model|gpt-/i,
             })
             .first();
-        await expect(modelButton).toBeEnabled({ timeout: 10000 });
+        await modelButton.waitFor({ state: "visible", timeout: 10000 });
         await modelButton.click();
         // Click the first option in the popover/command list
         const firstOption = this.page.locator('[role="option"]').first();
         await firstOption.waitFor({ state: "visible", timeout: 5000 });
         await firstOption.click();
     }
 
+    async selectModel(modelName: string): Promise<void> {
+        const modelButton = this.page
+            .locator("button")
+            .filter({ hasText: /Select model|gpt-/i })
+            .first();
+        await modelButton.waitFor({ state: "visible", timeout: 10000 });
+        await modelButton.click();
+        const option = this.page
+            .locator('[role="option"]')
+            .filter({ hasText: modelName })
+            .first();
+        await option.waitFor({ state: "visible", timeout: 5000 });
+        await option.click();
+    }
+
     async sendMessage(message: string): Promise<void> {
         const input = this.page.getByRole("textbox", {
             name: "Type a message...",
         });
-        await expect(input).toBeEnabled({ timeout: 5000 });
         await input.fill(message);
         await this.page.getByRole("button", { name: "Send" }).click();
     }
 
+    async waitForIdle(): Promise<void> {
+        const input = this.page.getByRole("textbox", {
+            name: "Type a message...",
+        });
+        await input
+            .and(this.page.locator(":enabled"))
+            .waitFor({ timeout: 10000 });
+    }
+
     async assertLastResponse(content: string): Promise<void> {
         await expect(
             this.page.locator(".bg-muted.rounded-2xl").last(),
         ).toContainText(content, { timeout: 5000 });
     }
+
+    async assertAssistantMessageModelName(
+        index: number,
+        modelName: string,
+    ): Promise<void> {
+        // Each assistant message is in a flex container with justify-start.
+        // The model-name label is the first <p> inside the message content area.
+        await expect(
+            this.page.locator("div.flex.justify-start .flex-1 > p").nth(index),
+        ).toHaveText(modelName, { timeout: 5000 });
+    }
 }
 
 export class Sidebar {

frontend/omni/docs/architecture/core.md

@@ -136,7 +136,7 @@ A manifest file has the following top-level shape:
 2. The root manifest's own `modules` are applied last and always win.
 
 **`collisionStrategy`** on a module entry controls what happens when that module's `id` already exists from an earlier include:
-- `"merge"` *(default)* — deep-merges `config`; incoming wins on shared keys. `dependencies` is shallow-merged; incoming wins on key collision.
+- `"merge"` *(default)* — deep-merges `config`; incoming wins on shared keys. `dependencies` is merged per key: string values follow the same "incoming wins" rule; **array values are unioned** (base items first, then new incoming items; duplicates dropped).
 - `"replace"` — incoming entry fully replaces the existing one.
 - `"drop"` — removes the existing entry; does not add the incoming one either.
 

frontend/omni/src/core/module-system/manifestJson.test.ts

@@ -157,7 +157,7 @@ describe("resolveManifest — collisionStrategy", () => {
         expect(svc?.config).toEqual({ nested: { a: 1, b: 2, c: 3 } });
     });
 
-    it("merge: merges dependencies records, incoming wins on key collision", async () => {
+    it("merge: merges dependencies records, incoming wins on string key collision", async () => {
         mockFetch({
             "/modules.json": manifest(
                 [
@@ -190,6 +190,68 @@ describe("resolveManifest — collisionStrategy", () => {
         });
     });
 
+    it("merge: unions array dependencies, base items first then new incoming items", async () => {
+        mockFetch({
+            "/modules.json": manifest(
+                [
+                    entry("router", {
+                        dependencies: {
+                            "module:routes": ["extra-route"],
+                        },
+                    }),
+                ],
+                { includes: [{ path: "/base.json" }] },
+            ),
+            "/base.json": manifest([
+                entry("router", {
+                    dependencies: {
+                        "module:routes": ["chat-route", "fallback-route"],
+                    },
+                }),
+            ]),
+        });
+
+        const result = await resolveManifest("/modules.json");
+        const router = result.modules.find((m) => m.id === "router");
+
+        expect(router?.dependencies?.["module:routes"]).toEqual([
+            "chat-route",
+            "fallback-route",
+            "extra-route",
+        ]);
+    });
+
+    it("merge: array union deduplicates items already present in the base", async () => {
+        mockFetch({
+            "/modules.json": manifest(
+                [
+                    entry("router", {
+                        dependencies: {
+                            "module:routes": ["chat-route", "extra-route"],
+                        },
+                    }),
+                ],
+                { includes: [{ path: "/base.json" }] },
+            ),
+            "/base.json": manifest([
+                entry("router", {
+                    dependencies: {
+                        "module:routes": ["chat-route", "fallback-route"],
+                    },
+                }),
+            ]),
+        });
+
+        const result = await resolveManifest("/modules.json");
+        const router = result.modules.find((m) => m.id === "router");
+
+        expect(router?.dependencies?.["module:routes"]).toEqual([
+            "chat-route",
+            "fallback-route",
+            "extra-route",
+        ]);
+    });
+
     it("replace: incoming entry fully replaces the included one", async () => {
         mockFetch({
             "/modules.json": manifest(

frontend/omni/src/core/module-system/manifestJson.ts

@@ -22,6 +22,9 @@ export interface ManifestEntry {
      * includes that overwrite earlier ones).
      *
      * - `merge` (default): deep-merge config; incoming wins on shared keys.
+     *   For dependency keys whose values are arrays in both base and incoming,
+     *   the arrays are unioned (base items first, then new incoming items;
+     *   duplicates are dropped). For string dependency values, incoming wins.
      * - `replace`: incoming entry fully replaces the existing one.
      * - `drop`: remove the existing entry; do not add this entry either.
      *
@@ -117,6 +120,23 @@ function applyModules(
     return result;
 }
 
+function mergeDependencies(
+    base: Record<string, string | string[]>,
+    incoming: Record<string, string | string[]>,
+): Record<string, string | string[]> {
+    const result: Record<string, string | string[]> = { ...base };
+    for (const [key, val] of Object.entries(incoming)) {
+        const existing = result[key];
+        if (Array.isArray(val) && Array.isArray(existing)) {
+            const seen = new Set(existing);
+            result[key] = [...existing, ...val.filter((v) => !seen.has(v))];
+        } else {
+            result[key] = val;
+        }
+    }
+    return result;
+}
+
 function deepMergeEntries(
     base: ManifestEntry,
     incoming: ManifestEntry,
@@ -127,10 +147,10 @@ function deepMergeEntries(
         base.dependencies !== undefined ||
         incoming.dependencies !== undefined
     ) {
-        merged.dependencies = {
-            ...(base.dependencies ?? {}),
-            ...(incoming.dependencies ?? {}),
-        };
+        merged.dependencies = mergeDependencies(
+            base.dependencies ?? {},
+            incoming.dependencies ?? {},
+        );
     }
 
     if (base.config !== undefined || incoming.config !== undefined) {

frontend/omni/src/modules/chat/ChatComponent.svelte

@@ -80,7 +80,7 @@ const providerGroups = $derived(
     })),
 );
 
-let messages = $state<UIMessage[]>([]);
+let messages = $state<UIMessage<{ modelName?: string }>[]>([]);
 let chatStatus = $state<"ready" | "submitted" | "streaming">("ready");
 
 const isIdle = $derived(
@@ -106,6 +106,7 @@ async function handleSend(text: string) {
             id: assistantMessageId,
             role: "assistant",
             parts: [{ type: "text", text: "" }],
+            metadata: { modelName: selectedModelData.modelName },
         },
     ];
     chatStatus = "submitted";
@@ -172,7 +173,6 @@ function makeMessageId(): string {
 		status={chatStatus}
 		{modelsLoading}
 		hasModels={availableModels.length > 0}
-		selectedModelName={selectedModelData?.modelName}
 	/>
 	{#if messages.length === 0 && availableModels.length > 0}
 		<ChatSuggestions onselect={handleSend} />

frontend/omni/src/modules/chat/ChatConversationArea.svelte

@@ -13,13 +13,11 @@ let {
     status,
     modelsLoading,
     hasModels,
-    selectedModelName,
 }: {
-    messages: UIMessage[];
+    messages: UIMessage<{ modelName?: string }>[];
     status: string;
     modelsLoading: boolean;
     hasModels: boolean;
-    selectedModelName: string | undefined;
 } = $props();
 
 let conversationEl = $state<HTMLElement | null>(null);
@@ -72,7 +70,7 @@ $effect(() => {
 		{/if}
 
 		{#each messages as message (message.id)}
-			<ChatMessageItem {message} {selectedModelName} />
+			<ChatMessageItem {message} />
 		{/each}
 
 		<!-- Streaming indicator -->

frontend/omni/src/modules/chat/ChatMessageItem.svelte

@@ -9,10 +9,8 @@ import * as Collapsible from "$lib/shadcnui/components/ui/collapsible/index.js";
 
 let {
     message,
-    selectedModelName,
 }: {
-    message: UIMessage;
-    selectedModelName: string | undefined;
+    message: UIMessage<{ modelName?: string }>;
 } = $props();
 
 function renderMarkdown(text: string): string {
@@ -51,7 +49,7 @@ function renderMarkdown(text: string): string {
 			>
 				{message.role === "user"
 					? "You"
-					: (selectedModelName ?? "Assistant")}
+					: (message.metadata?.modelName ?? "Assistant")}
 			</p>
 			<div
 				class="flex flex-col gap-2 {message.role === 'user'