fix(reply): auto-inject replyToCurrent for reply threading

replyToMode "first"/"all" only filters replyToId but never generates
it — that required the LLM to emit [[reply_to_current]] tags. Inject
replyToCurrent:true on all payloads so applyReplyTagsToPayload sets
replyToId=currentMessageId, then let the existing mode filter decide
which replies keep threading (first only, all, or off).

Covers both final reply path (reply-payloads.ts) and block streaming
path (agent-runner-execution.ts).

src/auto-reply/reply/agent-runner-execution.ts

@@ -378,7 +378,7 @@ export async function runAgentTurnWithFallback(params: {
                       mediaUrl: payload.mediaUrls?.[0],
                       replyToId: payload.replyToId,
                       replyToTag: payload.replyToTag,
-                      replyToCurrent: payload.replyToCurrent,
+                      replyToCurrent: true,
                     },
                     currentMessageId,
                   );