Add DM support, friend identification, and target pruning

React in 1:1 DMs alongside servers/groups, surface the resolved friend
username at startup and in the stats panel, verify reactions actually
stick after adding them (with jump links for manual spot-checking),
and prune stale targets from stats on each run so only the currently
mutual set is shown.

bot/display.py

@@ -1,5 +1,5 @@
 import asyncio
-from typing import List
+from typing import List, Optional
 
 from rich.console import Console
 from rich.live import Live
@@ -8,8 +8,10 @@ from rich.table import Table
 
 from bot.storage import Storage
 
+_TYPE_LABELS = {"guild": "server", "group_dm": "group", "dm": "DM"}
 
-def _render(stats: List[dict]) -> Panel:
+
+def _render(stats: List[dict], friend_label: Optional[str] = None) -> Panel:
     table = Table(expand=True)
     table.add_column("Target")
     table.add_column("Type")
@@ -21,7 +23,7 @@ def _render(stats: List[dict]) -> Panel:
         total += row["reaction_count"]
         table.add_row(
             row["name"] or row["target_id"],
-            "server" if row["target_type"] == "guild" else "group",
+            _TYPE_LABELS.get(row["target_type"], row["target_type"]),
             str(row["reaction_count"]),
             row["last_reaction_at"] or "-",
         )
@@ -29,7 +31,8 @@ def _render(stats: List[dict]) -> Panel:
     if not stats:
         table.add_row("(no targets discovered yet)", "-", "-", "-")
 
-    return Panel(table, title=f"Reaction stats — total: {total}", border_style="cyan")
+    who = f" for {friend_label}" if friend_label else ""
+    return Panel(table, title=f"Reaction stats{who} — total: {total}", border_style="cyan")
 
 
 class StatsDisplay:
@@ -39,6 +42,7 @@ class StatsDisplay:
     def __init__(self, console: Console, storage: Storage):
         self.console = console
         self.storage = storage
+        self.friend_label: Optional[str] = None
         self._live = Live(
             _render([]),
             console=console,
@@ -53,10 +57,13 @@ class StatsDisplay:
     def __exit__(self, *exc_info):
         return self._live.__exit__(*exc_info)
 
+    def set_friend(self, label: str) -> None:
+        self.friend_label = label
+
     def refresh_sync(self) -> None:
         stats = self.storage.get_stats()
-        self._live.update(_render(stats))
+        self._live.update(_render(stats, self.friend_label))
 
     async def refresh(self) -> None:
         stats = await asyncio.to_thread(self.storage.get_stats)
-        self._live.update(_render(stats))
+        self._live.update(_render(stats, self.friend_label))