feat: relay AG-side user messages to Discord via chat_snapshots

extension/src/extension.ts

@@ -1843,7 +1843,39 @@ function setupMonitor() {
             const userInputIdx = bestSession.lastUserInputStepIndex ?? -1;
             if (userInputIdx > lastUserInputStepIdx) {
                 lastUserInputStepIdx = userInputIdx;
-                logToFile(`[RESPONSE-CAPTURE] user input detected at step ${userInputIdx}`);
+                logToFile(`[USER-MSG] user input detected at step ${userInputIdx}, capturing...`);
+                // Fetch user message content and relay to Discord
+                try {
+                    const umResp = await sdk.ls.rawRPC('GetCascadeTrajectorySteps', {
+                        cascadeId: bestSessionId,
+                        stepOffset: userInputIdx,
+                        verbosity: 1,
+                    });
+                    if (umResp?.steps?.length > 0) {
+                        const umStep = umResp.steps[0];
+                        // User message text can be in various fields
+                        const umText = umStep?.userMessage?.text
+                            || umStep?.userMessage?.rawText
+                            || umStep?.plannerResponse?.rawText
+                            || umStep?.metadata?.toolCall?.argumentsJson
+                            || '';
+                        if (umText.length > 2) {
+                            const truncated = umText.length > 800
+                                ? umText.substring(0, 800) + '\n\n_(이하 생략)_'
+                                : umText;
+                            writeChatSnapshot(`👤 **사용자 (AG 직접 입력)**\n\n${truncated}`);
+                            logToFile(`[USER-MSG] relayed ${umText.length} chars from step ${userInputIdx}`);
+                        } else {
+                            // Fallback: just notify that user sent input
+                            writeChatSnapshot(`👤 **사용자 (AG 직접 입력)** — _(내용 추출 불가)_`);
+                            logToFile(`[USER-MSG] step ${userInputIdx} text empty, sent fallback`);
+                        }
+                    }
+                } catch (umErr: any) {
+                    logToFile(`[USER-MSG] capture error: ${umErr.message?.substring(0, 100)}`);
+                    // Still notify discord about user input even without content
+                    writeChatSnapshot(`👤 **사용자 (AG 직접 입력)** — _(캡처 실패)_`);
+                }
             }
 
             if (wasRunning && !isRunning && currentCount > lastResponseCaptureStep) {