Two-phase backlog scan with self-healing found-count tracking

Split each channel's backlog scan into a find phase (settles the
found count first) and a react phase, so the progress display no
longer grows both numbers in lockstep. Found messages are logged in
a dedicated, message_id-deduped table and recovered across restarts
independent of the resume checkpoint, so nothing found is silently
abandoned if the script stops mid-react.

Also drops the separately-maintained messages_found counter, which
proved prone to drift under repeated interruptions/rescans, in favor
of computing it live from the dedup table - self-healing regardless
of how many times a channel gets rescanned.

bot/display.py

@@ -4,6 +4,7 @@ from typing import List, Optional
 from rich.console import Console
 from rich.live import Live
 from rich.panel import Panel
+from rich.progress_bar import ProgressBar
 from rich.table import Table
 
 from bot.storage import Storage
@@ -15,24 +16,32 @@ def _render(stats: List[dict], friend_label: Optional[str] = None) -> Panel:
     table = Table(expand=True)
     table.add_column("Target")
     table.add_column("Type")
-    table.add_column("Reactions", justify="right")
+    table.add_column("Progress", ratio=1)
+    table.add_column("Reacted/Found", justify="right")
     table.add_column("Last reaction (UTC)")
 
-    total = 0
+    total_reacted = 0
+    total_found = 0
     for row in stats:
-        total += row["reaction_count"]
+        reacted = row["reaction_count"]
+        found = max(row["messages_found"], reacted)  # found can never be less than reacted
+        total_reacted += reacted
+        total_found += found
+
+        bar = ProgressBar(total=max(found, reacted, 1), completed=reacted, width=None)
         table.add_row(
             row["name"] or row["target_id"],
             _TYPE_LABELS.get(row["target_type"], row["target_type"]),
-            str(row["reaction_count"]),
+            bar,
+            f"{reacted}/{found}",
             row["last_reaction_at"] or "-",
         )
 
     if not stats:
-        table.add_row("(no targets discovered yet)", "-", "-", "-")
+        table.add_row("(no targets discovered yet)", "-", "-", "-", "-")
 
     who = f" for {friend_label}" if friend_label else ""
-    return Panel(table, title=f"Reaction stats{who} — total: {total}", border_style="cyan")
+    return Panel(table, title=f"Reaction stats{who} — total: {total_reacted}/{total_found}", border_style="cyan")
 
 
 class StatsDisplay: