stage-5: full discord-claude chat integration

Message router, typing indicator, emoji reactions, auto start/resume sessions, message splitting >2000 chars. 34 new tests (141 total).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/router.py

@@ -0,0 +1,75 @@
+"""Echo Core message router — routes messages to Claude or commands."""
+
+import logging
+from src.config import Config
+from src.claude_session import send_message, clear_session, get_active_session, list_sessions
+
+log = logging.getLogger(__name__)
+
+# Module-level config instance (lazy singleton)
+_config: Config | None = None
+
+
+def _get_config() -> Config:
+    """Return the module-level config, creating it on first access."""
+    global _config
+    if _config is None:
+        _config = Config()
+    return _config
+
+
+def route_message(channel_id: str, user_id: str, text: str, model: str | None = None) -> tuple[str, bool]:
+    """Route an incoming message. Returns (response_text, is_command).
+
+    If text starts with / it's a command (handled here for text-based commands).
+    Otherwise it goes to Claude via send_message (auto start/resume).
+    """
+    text = text.strip()
+
+    # Text-based commands (not slash commands — these work in any adapter)
+    if text.lower() == "/clear":
+        cleared = clear_session(channel_id)
+        if cleared:
+            return "Session cleared.", True
+        return "No active session.", True
+
+    if text.lower() == "/status":
+        return _status(channel_id), True
+
+    if text.startswith("/"):
+        return f"Unknown command: {text.split()[0]}", True
+
+    # Regular message → Claude
+    if not model:
+        # Get channel default model or global default
+        channel_cfg = _get_channel_config(channel_id)
+        model = (channel_cfg or {}).get("default_model") or _get_config().get("bot.default_model", "sonnet")
+
+    try:
+        response = send_message(channel_id, text, model=model)
+        return response, False
+    except Exception as e:
+        log.error(f"Claude error for channel {channel_id}: {e}")
+        return f"Error: {e}", False
+
+
+def _status(channel_id: str) -> str:
+    """Build status message for a channel."""
+    session = get_active_session(channel_id)
+    if not session:
+        return "No active session."
+
+    model = session.get("model", "unknown")
+    sid = session.get("session_id", "unknown")[:12]
+    count = session.get("message_count", 0)
+
+    return f"Model: {model} | Session: {sid}... | Messages: {count}"
+
+
+def _get_channel_config(channel_id: str) -> dict | None:
+    """Find channel config by ID."""
+    channels = _get_config().get("channels", {})
+    for alias, ch in channels.items():
+        if ch.get("id") == channel_id:
+            return ch
+    return None