feat: LLM intent router, direct chat execution, and Memory V2 light intervention

Wire chat intent routing with direct_chat on regular sessions, skill-selected
short-circuit to Agent, memory light/heavy intervention tiers, and fix direct
chat UI stuck streaming after completion.

Co-authored-by: Cursor <cursoragent@cursor.com>

session-snapshot.mjs

@@ -67,8 +67,35 @@ function resolveDisplayTitle(session, messages) {
   return deriveTitleFromMessages(messages);
 }
 
+async function syncConversationMemory({
+  memoryV2 = null,
+  conversationMemoryService = null,
+  sessionId,
+  userId,
+  messages,
+  logger = console,
+} = {}) {
+  if (memoryV2?.write) {
+    const result = await memoryV2.write({ userId, sessionId, messages });
+    if (result?.skipped && result?.reason === 'disabled') return result;
+    if (!result?.ok && !result?.skipped) {
+      logger?.warn?.(
+        '[snapshot] memory v2 write degraded:',
+        result?.reason ?? 'unknown',
+      );
+    }
+    return result;
+  }
+  if (conversationMemoryService?.isEnabled?.()) {
+    return conversationMemoryService.saveAndAnalyze(sessionId, userId, messages);
+  }
+  return null;
+}
+
 export function createSessionSnapshotService(pool, options = {}) {
   const conversationMemoryService = options.conversationMemoryService ?? null;
+  const memoryV2 = options.memoryV2 ?? null;
+  const logger = options.logger ?? console;
 
   function isEnabled() {
     return process.env.SESSION_SNAPSHOT_CACHE_ENABLED !== '0';
@@ -145,15 +172,20 @@ export function createSessionSnapshotService(pool, options = {}) {
           now,
         ],
       );
-      if (conversationMemoryService?.isEnabled?.()) {
-        void conversationMemoryService
-          .saveAndAnalyze(sessionId, userId, messages)
-          .catch((err) => {
-            console.warn(
-              '[snapshot] conversation memory sync failed:',
-              err instanceof Error ? err.message : err,
-            );
-          });
+      if (memoryV2?.write || conversationMemoryService?.isEnabled?.()) {
+        void syncConversationMemory({
+          memoryV2,
+          conversationMemoryService,
+          sessionId,
+          userId,
+          messages,
+          logger,
+        }).catch((err) => {
+          logger?.warn?.(
+            '[snapshot] conversation memory sync failed:',
+            err instanceof Error ? err.message : err,
+          );
+        });
       }
     } catch (err) {
       // Non-fatal: log and continue; caller falls back to Goose.