fix: add missing type discriminators to storybook chat messages

The MarkdownTables story was emitting messages without the required
`type: "message"` field. The `as WorkspaceChatMessage` type casts
hid this from TypeScript, causing messages to not be recognized
by the chat processor and rendering "No Messages Yet" instead.

Also fix ChatEventProcessor tests that had invalid event shapes:
- Remove invalid `role`/`timestamp` from stream-start events
- Add missing `workspaceId`/`tokens` to delta events

Author: ThomasK33

src/browser/App.stories.tsx

@@ -1140,17 +1140,16 @@ export const MarkdownTables: Story = {
       setTimeout(() => {
         // User message
         emit({
+          type: "message",
           id: "msg-1",
           role: "user",
           parts: [{ type: "text", text: "Show me some table examples" }],
-          metadata: {
-            historySequence: 1,
-            timestamp: STABLE_TIMESTAMP,
-          },
-        } as WorkspaceChatMessage);
+          createdAt: new Date(STABLE_TIMESTAMP),
+        });
 
         // Assistant message with tables
         emit({
+          type: "message",
           id: "msg-2",
           role: "assistant",
           parts: [
@@ -1226,10 +1225,10 @@ These tables should render cleanly without any disruptive copy or download actio
             },
             duration: 2000,
           },
-        } as WorkspaceChatMessage);
+        });
 
         // Mark as caught up
-        emit({ type: "caught-up" } as WorkspaceChatMessage);
+        emit({ type: "caught-up" });
       }, 100);
     };
 

src/browser/utils/messages/ChatEventProcessor.test.ts

@@ -1,43 +1,47 @@
 import { createChatEventProcessor } from "./ChatEventProcessor";
-import type { WorkspaceChatMessage } from "@/common/orpc/types";
 
 describe("ChatEventProcessor - Reasoning Delta", () => {
   it("should merge consecutive reasoning deltas into a single part", () => {
     const processor = createChatEventProcessor();
+    const workspaceId = "ws-1";
     const messageId = "msg-1";
 
     // Start stream
     processor.handleEvent({
       type: "stream-start",
-      workspaceId: "ws-1",
+      workspaceId,
       messageId,
-      role: "assistant",
       model: "gpt-4",
-      timestamp: 1000,
       historySequence: 1,
-    } as WorkspaceChatMessage);
+    });
 
     // Send reasoning deltas
     processor.handleEvent({
       type: "reasoning-delta",
+      workspaceId,
       messageId,
       delta: "Thinking",
+      tokens: 1,
       timestamp: 1001,
-    } as WorkspaceChatMessage);
+    });
 
     processor.handleEvent({
       type: "reasoning-delta",
+      workspaceId,
       messageId,
       delta: " about",
+      tokens: 1,
       timestamp: 1002,
-    } as WorkspaceChatMessage);
+    });
 
     processor.handleEvent({
       type: "reasoning-delta",
+      workspaceId,
       messageId,
       delta: " this...",
+      tokens: 1,
       timestamp: 1003,
-    } as WorkspaceChatMessage);
+    });
 
     const messages = processor.getMessages();
     expect(messages).toHaveLength(1);
@@ -55,42 +59,47 @@ describe("ChatEventProcessor - Reasoning Delta", () => {
 
   it("should separate reasoning parts if interrupted by other content (though unlikely in practice)", () => {
     const processor = createChatEventProcessor();
+    const workspaceId = "ws-1";
     const messageId = "msg-1";
 
     // Start stream
     processor.handleEvent({
       type: "stream-start",
-      workspaceId: "ws-1",
+      workspaceId,
       messageId,
-      role: "assistant",
       model: "gpt-4",
-      timestamp: 1000,
       historySequence: 1,
-    } as WorkspaceChatMessage);
+    });
 
     // Reasoning 1
     processor.handleEvent({
       type: "reasoning-delta",
+      workspaceId,
       messageId,
       delta: "Part 1",
+      tokens: 1,
       timestamp: 1001,
-    } as WorkspaceChatMessage);
+    });
 
     // Text delta (interruption - although usually reasoning comes before text)
     processor.handleEvent({
       type: "stream-delta",
+      workspaceId,
       messageId,
       delta: "Some text",
+      tokens: 2,
       timestamp: 1002,
-    } as WorkspaceChatMessage);
+    });
 
     // Reasoning 2
     processor.handleEvent({
       type: "reasoning-delta",
+      workspaceId,
       messageId,
       delta: "Part 2",
+      tokens: 1,
       timestamp: 1003,
-    } as WorkspaceChatMessage);
+    });
 
     const messages = processor.getMessages();
     const parts = messages[0].parts;