feat: support all chat types in channel discovery and enrich bot messages

Channel Discovery:
- Remove channel/supergroup filter from getAccountChats — all chat types
  (private, groups, Saved Messages, etc.) are now discoverable as sources
- Detect and label the self-chat as "Saved Messages" via getMe
- Update channel picker dialog to accept any chat type string

Bot Rich Messages:
- Enhance package send preview with creator, file count, tags, and source
  channel info in MarkdownV2 caption
- Include tags in new_package subscription notifications
- Expand getPendingSendRequest to fetch richer package data

Performance:
- Reviewed pipeline for many-channel load — getChats pagination fix and
  per-channel getChat pre-load from prior commit address the main concerns
- Channels with no new messages skip in 2-3 API calls

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

bot/src/db/queries.ts

@@ -115,9 +115,15 @@ export async function getPendingSendRequest(requestId: string) {
         select: {
           id: true,
           fileName: true,
+          fileSize: true,
+          fileCount: true,
+          creator: true,
+          tags: true,
+          archiveType: true,
           destChannelId: true,
           destMessageId: true,
           previewData: true,
+          sourceChannel: { select: { title: true, telegramId: true } },
         },
       },
       telegramLink: true,

bot/src/send-listener.ts

@@ -134,9 +134,22 @@ async function processSendRequest(requestId: string): Promise<void> {
       throw new Error("No global destination channel configured");
     }
 
-    // Send preview if available
+    // Send preview with rich caption if available
     if (pkg.previewData) {
-      const caption = `📦 *${pkg.fileName}*\n\nSent from Dragon's Stash`;
+      const lines: string[] = [];
+      lines.push(`📦 *${escapeMarkdown(pkg.fileName)}*`);
+      if (pkg.creator) lines.push(`👤 ${escapeMarkdown(pkg.creator)}`);
+      if (pkg.fileCount > 0) lines.push(`📁 ${pkg.fileCount} files`);
+      if (pkg.tags && pkg.tags.length > 0) {
+        lines.push(`🏷️ ${pkg.tags.map((t: string) => escapeMarkdown(t)).join(", ")}`);
+      }
+      if (pkg.sourceChannel) {
+        lines.push(`📡 Source: ${escapeMarkdown(pkg.sourceChannel.title)}`);
+      }
+      lines.push("");
+      lines.push("_Sent from Dragon's Stash_");
+
+      const caption = lines.join("\n");
       await sendPhotoMessage(targetUserId, Buffer.from(pkg.previewData), caption);
     }
 
@@ -189,6 +202,9 @@ async function handleNewPackage(payload: string): Promise<void> {
         `🔔 <b>New package matching your subscriptions:</b>`,
         ``,
         `📦 <b>${escapeHtml(data.fileName)}</b>${creator}`,
+        ...(data.tags && data.tags.length > 0
+          ? [`🏷️ ${data.tags.map((t: string) => escapeHtml(t)).join(", ")}`]
+          : []),
         ``,
         `Matched: ${patterns.map((p) => `"${escapeHtml(p)}"`).join(", ")}`,
         ``,
@@ -213,3 +229,7 @@ async function handleNewPackage(payload: string): Promise<void> {
 function escapeHtml(text: string): string {
   return text.replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;");
 }
+
+function escapeMarkdown(text: string): string {
+  return text.replace(/([_*[\]()~`>#+\-=|{}.!\\])/g, "\\$1");
+}