Add Wordle, welcome system, integrations, and update roadmap

- Add Wordle game engine with daily puzzles, hard mode, stats, and share
- Add welcome module (react-to-join onboarding, Space join DMs)
- Add Ollama LLM integration (!ask), Minecraft RCON whitelist (!minecraft)
- Add !trivia, !champion, !agent, !health commands
- Add DM routing for Wordle (games in DMs, share to public room)
- Update README: reflect Phase 4 completion, hookshot webhook setup,
  infrastructure migration (LXC 151/109 to large1), Spam and Stuff room,
  all 12 webhook connections with UUIDs and transform notes

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

callbacks.py

@@ -1,10 +1,11 @@
 import logging
 from functools import wraps
 
-from nio import AsyncClient, RoomMessageText
+from nio import AsyncClient, RoomMessageText, UnknownEvent
 
 from config import BOT_PREFIX, MATRIX_USER_ID
 from commands import COMMANDS, metrics
+from welcome import handle_welcome_reaction, handle_space_join, SPACE_ROOM_ID
 
 logger = logging.getLogger("matrixbot")
 
@@ -60,3 +61,54 @@ class Callbacks:
         metrics.record_command(cmd_name)
         wrapped = handle_command_errors(handler)
         await wrapped(self.client, room.room_id, event.sender, args)
+
+    async def reaction(self, room, event):
+        """Handle m.reaction events (sent as UnknownEvent by matrix-nio)."""
+        # Ignore events from before startup
+        if self.startup_sync_token is None:
+            return
+
+        # Ignore our own reactions
+        if event.sender == MATRIX_USER_ID:
+            return
+
+        # m.reaction events come as UnknownEvent with type "m.reaction"
+        if not hasattr(event, "source"):
+            return
+
+        content = event.source.get("content", {})
+        relates_to = content.get("m.relates_to", {})
+        if relates_to.get("rel_type") != "m.annotation":
+            return
+
+        reacted_event_id = relates_to.get("event_id", "")
+        key = relates_to.get("key", "")
+
+        await handle_welcome_reaction(
+            self.client, room.room_id, event.sender, reacted_event_id, key
+        )
+
+    async def member(self, room, event):
+        """Handle m.room.member events — watch for Space joins."""
+        # Ignore events from before startup
+        if self.startup_sync_token is None:
+            return
+
+        # Only care about the Space
+        if room.room_id != SPACE_ROOM_ID:
+            return
+
+        # Ignore our own membership changes
+        if event.state_key == MATRIX_USER_ID:
+            return
+
+        # Only trigger on joins (not leaves, bans, etc.)
+        if event.membership != "join":
+            return
+
+        # Check if this is a new join (prev was not "join")
+        prev = event.prev_membership if hasattr(event, "prev_membership") else None
+        if prev == "join":
+            return  # Already was a member, this is a profile update or similar
+
+        await handle_space_join(self.client, event.state_key)