fix: stop treating empty content as NO_REPLY, detect tool calls

Problems fixed:
1. before_message_write treated empty content (isEmpty) as NO_REPLY.
   Tool-call-only assistant messages (thinking + toolCall, no text)
   had empty extracted text, causing false NO_REPLY detection.
   In single-agent channels this immediately set turn to dormant,
   blocking all subsequent responses for the entire model run.

2. Added explicit toolCall/tool_call/tool_use detection in
   before_message_write — skip turn processing for intermediate
   tool-call messages entirely.

3. no-reply-api/server.mjs: default model name changed from
   'dirigent-no-reply-v1' to 'no-reply' to match the configured
   model id in openclaw.json, fixing model list discovery.

Changes:
- plugin/hooks/before-message-write.ts: toolCall detection + remove isEmpty
- plugin/hooks/message-sent.ts: remove isEmpty from wasNoReply
- no-reply-api/server.mjs: fix default model name
- dist/dirigent/index.ts: same fixes applied to monolithic build
- dist/no-reply-api/server.mjs: same model name fix

plugin/hooks/message-sent.ts

@@ -74,13 +74,13 @@ export function registerMessageSentHook(deps: MessageSentDeps): void {
       const policy = resolvePolicy(live, channelId, policyState.channelPolicies as Record<string, any>);
 
       const trimmed = content.trim();
-      const isEmpty = trimmed.length === 0;
       const isNoReply = /^NO_REPLY$/i.test(trimmed) || /^HEARTBEAT_OK$/i.test(trimmed);
       const lastChar = trimmed.length > 0 ? Array.from(trimmed).pop() || "" : "";
       const hasEndSymbol = !!lastChar && policy.endSymbols.includes(lastChar);
       const waitId = live.waitIdentifier || "👤";
       const hasWaitIdentifier = !!lastChar && lastChar === waitId;
-      const wasNoReply = isEmpty || isNoReply;
+      // Only treat explicit NO_REPLY/HEARTBEAT_OK keywords as no-reply.
+      const wasNoReply = isNoReply;
 
       if (key && sessionTurnHandled.has(key)) {
         sessionTurnHandled.delete(key);
@@ -100,7 +100,7 @@ export function registerMessageSentHook(deps: MessageSentDeps): void {
 
       if (wasNoReply || hasEndSymbol) {
         const nextSpeaker = onSpeakerDone(channelId, accountId, wasNoReply);
-        const trigger = wasNoReply ? (isEmpty ? "empty" : "no_reply_keyword") : "end_symbol";
+        const trigger = wasNoReply ? "no_reply_keyword" : "end_symbol";
         api.logger.info(
           `dirigent: turn onSpeakerDone channel=${channelId} from=${accountId} next=${nextSpeaker ?? "dormant"} trigger=${trigger}`,
         );