feat: add selectedReposCount to wa_chat_message_sent event

- Add selectedReposCount field to wa_chat_message_sent event type
- Include selectedReposCount in chat message events for both streaming and blocking endpoints
- This provides analytics on how many repositories users select when asking questions

Co-authored-by: Brendan Kellam <brendan@sourcebot.dev>

Author: cursoragent

packages/web/src/app/api/(server)/chat/blocking/route.ts

@@ -164,6 +164,7 @@ export const POST = apiHandler(async (request: NextRequest) => {
             await captureEvent('wa_chat_message_sent', {
                 chatId: chat.id,
                 messageCount: 1,
+                selectedReposCount: selectedRepos.length,
                 ...(env.EXPERIMENT_ASK_GH_ENABLED === 'true' ? {
                     selectedRepos: selectedRepos.map(r => r.value)
                 } : {}),

packages/web/src/app/api/(server)/chat/route.ts

@@ -103,6 +103,7 @@ export const POST = apiHandler(async (req: NextRequest) => {
             await captureEvent('wa_chat_message_sent', {
                 chatId: id,
                 messageCount: messages.length,
+                selectedReposCount: expandedRepos.length,
                 ...(env.EXPERIMENT_ASK_GH_ENABLED === 'true' ? { selectedRepos: expandedRepos } : {}),
             } );
 

packages/web/src/lib/posthogEvents.ts

@@ -157,6 +157,7 @@ export type PosthogEventMap = {
     wa_chat_message_sent: {
         chatId: string,
         messageCount: number,
+        selectedReposCount: number,
         /**
          * @note this field will only be populated when
          * the EXPERIMENT_ASK_GH_ENABLED environment variable