feat: wait for human reply (waitIdentifier 👤)

- Add waitIdentifier config (default: 👤) to DirigentConfig and plugin schema
- Prompt injection: tells agents to end with 👤 when they need a human reply,
  warns to use sparingly (only when human is actively participating)
- Detection in before_message_write and message_sent hooks
- Turn manager: new waitingForHuman state
  - checkTurn() blocks all agents when waiting
  - onNewMessage() clears state on human message
  - Non-human messages ignored while waiting
  - resetTurn() also clears waiting state
- All agents routed to no-reply model during waiting state
- Update docs (FEAT.md, CHANGELOG.md, TASKLIST.md, README.md)

plugin/rules.ts

@@ -10,6 +10,8 @@ export type DirigentConfig = {
   endSymbols?: string[];
   /** Scheduling identifier sent by moderator to activate agents (default: ➡️) */
   schedulingIdentifier?: string;
+  /** Wait identifier: agent ends with this when waiting for a human reply (default: 👤) */
+  waitIdentifier?: string;
   noReplyProvider: string;
   noReplyModel: string;
   /** Discord bot token for the moderator bot (used for turn handoff messages) */