fix: collect response text from event subscription instead of prompt return

session.prompt() non-blocking — возвращает объект-приём, а не текст.
Текст ответа приходит через ctx.event.subscribe() как live-only events.

Подход:
- pendingResponses Map: sessionID -> {resolve, reject, timer}
- Event subscription: парсит события, извлекает текст из assistant сообщений
- Message handler: создаёт Promise, ждёт события (timeout 30s)
- Парсим несколько структур событий на всякий случай

index.ts

@@ -93,17 +93,72 @@ async function runPlugin(ctx: any, options: any, dataDir: string) {
     // Track Matrix context per OpenCode session
     const sessionContextMap = new Map<string, { roomId: string; threadRootId: string; context: any }>()
 
-    // V2 Event subscription for response streaming
+    // Pending prompt responses — maps sessionID -> { resolve, reject, timer }
+    const pendingResponses = new Map<string, {
+      resolve: (text: string) => void
+      reject: (err: any) => void
+      timer: ReturnType<typeof setTimeout>
+    }>()
+
+    // V2 Event subscription — collects assistant response text from events
     void (async () => {
       try {
         for await (const event of ctx.event.subscribe({ signal: eventController.signal })) {
-          const eventType = typeof event === "object" && event !== null && "type" in event ? (event as { type: string }).type : ""
-          if (eventType === "session.updated") {
-            const sessionId = (event as { sessionID?: string }).sessionID
-            if (!sessionId) continue
-            const update = (event as { update?: { type: string; content?: string; toolName?: string } }).update
-            if (!update) continue
-            log(`V2 event: session=${sessionId}, update.type=${update.type}`)
+          // Parse event — V2EventEncoded is a JSON string
+          let eventData: any = event
+          if (typeof event === "string") {
+            try {
+              eventData = JSON.parse(event)
+            } catch { /* not JSON, use raw */ }
+          }
+
+          const eventType = eventData?.type || ""
+          const sessionId = eventData?.sessionID || eventData?.session?.id || ""
+
+          // Check if this event contains assistant response text for a pending prompt
+          if (sessionId && pendingResponses.has(sessionId)) {
+            const pending = pendingResponses.get(sessionId)!
+
+            // Extract text from various event structures
+            let responseText = ""
+
+            // Try: event.messages[].content[].text
+            const messages = eventData?.messages || eventData?.data?.messages || eventData?.update?.messages
+            if (Array.isArray(messages)) {
+              for (const msg of messages) {
+                if (msg?.type === "assistant" || msg?.role === "assistant") {
+                  const content = msg?.content || msg?.text
+                  if (typeof content === "string") responseText += content
+                  else if (Array.isArray(content)) {
+                    for (const part of content) {
+                      if (part?.type === "text" && part?.text) responseText += part.text
+                    }
+                  }
+                }
+              }
+            }
+
+            // Try: event.update.content (simple text update)
+            if (!responseText && eventData?.update?.content) {
+              responseText = String(eventData.update.content)
+            }
+
+            // Try: event.payload.text (synthetic message)
+            if (!responseText && eventData?.payload?.text) {
+              responseText = eventData.payload.text
+            }
+
+            // Try: event.data.text (generate response)
+            if (!responseText && eventData?.data?.text) {
+              responseText = eventData.data.text
+            }
+
+            if (responseText) {
+              log(`Collected response text (${responseText.length} chars) for session ${sessionId}`)
+              clearTimeout(pending.timer)
+              pendingResponses.delete(sessionId)
+              pending.resolve(responseText)
+            }
           }
         }
       } catch (err) {
@@ -176,11 +231,22 @@ async function runPlugin(ctx: any, options: any, dataDir: string) {
       }
 
       try {
-        const result = await ctx.session.prompt({
+        // Trigger prompt — returns admission receipt, not response text
+        await ctx.session.prompt({
           sessionID: opencodeSessionId,
           text: query,
         })
-        const responseText = result ? String(result) : "No response"
+
+        // Wait for response text from event subscription
+        const responsePromise = new Promise<string>((resolve, reject) => {
+          const timeout = setTimeout(() => {
+            pendingResponses.delete(opencodeSessionId)
+            reject(new Error("Timeout waiting for response (30s)"))
+          }, 30_000)
+          pendingResponses.set(opencodeSessionId, { resolve, reject, timer: timeout })
+        })
+
+        const responseText = await responsePromise
         session.outputChars += responseText.length
         await matrix.sendReply(context, responseText)
       } catch (err: any) {