Fix voice text channel detection & cross-channel hour purge (#1)

Two fixes in `src/handlers.rs`:

**1. Voice text channel detection**
Messages sent in voice channel text threads have a different `channel_id` than the parent voice channel. The `message` handler now falls through to check `msg.thread.parent_id` — if the parent is a watched channel, it catches them.

**2. Cross-channel 1-hour message purge**
When a user is banned, the bot now fetches the last 10 messages from **every** watched channel in the guild and bulk-deletes any from that user within the past hour (snowflake timestamp boundary). Catches messages sent before the trigger message hit.

Reviewed-on: http://git.infernonode.com/HotaruBlaze/Cinderwatch/pulls/1
Co-authored-by: Hermes-Neo <hermes-neo@noreply.localhost>
Co-committed-by: Hermes-Neo <hermes-neo@noreply.localhost>

src/handlers.rs

@@ -4,10 +4,14 @@ use serenity::all::ActivityData;
 use serenity::model::channel::MessageFlags;
 use serenity::{
     async_trait,
-    builder::{CreateAttachment, CreateMessage},
+    builder::{CreateAttachment, CreateMessage, GetMessages},
     client::Context,
     model::{
-        application::Interaction, channel::Message, gateway::Ready, guild::Guild, id::GuildId,
+        application::Interaction,
+        channel::Message,
+        gateway::Ready,
+        guild::Guild,
+        id::{GuildId, MessageId},
         user::OnlineStatus,
     },
 };
@@ -85,9 +89,31 @@ impl serenity::client::EventHandler for Handler {
             None => return,
         };
 
-        match self.db.is_watched_channel(guild_id, msg.channel_id) {
+        // Check if the channel itself is watched, or if this message is in a
-            Ok(true) => {}
+        // thread (e.g. a voice text channel) whose parent channel is watched.
-            _ => return,
+        let is_watched = self
+            .db
+            .is_watched_channel(guild_id, msg.channel_id)
+            .unwrap_or(false);
+
+        if !is_watched {
+            if let Some(ref thread_channel) = msg.thread {
+                if let Some(parent_id) = thread_channel.parent_id {
+                    if self
+                        .db
+                        .is_watched_channel(guild_id, parent_id)
+                        .unwrap_or(false)
+                    {
+                        // This message is in a thread whose parent is watched
+                    } else {
+                        return;
+                    }
+                } else {
+                    return;
+                }
+            } else {
+                return;
+            }
         }
 
         if let Err(e) = self
@@ -191,6 +217,38 @@ impl Handler {
 
         let _ = msg.delete(&ctx.http).await;
 
+        // Purge this user's messages from ALL watched channels within the past hour.
+        let watched = match self.db.get_watched_channels(guild_id) {
+            Ok(channels) => channels,
+            Err(e) => {
+                eprintln!("Failed to get watched channels: {:?}", e);
+                vec![]
+            }
+        };
+
+        let one_hour_ago = msg.id.get() - (3_600_000 << 22);
+
+        for channel_id in watched {
+            let Ok(batch) = channel_id
+                .messages(&ctx.http, GetMessages::new().limit(10))
+                .await
+            else {
+                continue;
+            };
+
+            let to_delete: Vec<MessageId> = batch
+                .iter()
+                .filter(|m| m.author.id == msg.author.id && m.id.get() >= one_hour_ago)
+                .map(|m| m.id)
+                .collect();
+
+            for chunk in to_delete.chunks(100) {
+                if let Err(e) = channel_id.delete_messages(&ctx.http, chunk).await {
+                    eprintln!("Failed to bulk delete in {channel_id}: {e:?}");
+                }
+            }
+        }
+
         let ban_reason = self
             .db
             .get_ban_reason(guild_id)