feat: Add ShareCard page for bot sharing with QR code

- Add ShareCard action to BotsController for generating bot share page
- Create ShareCard.cshtml view with gradient card design
- Generate QR code for Telegram bot link using QRCode.js
- Display bot info including type, status, description, and version
- Add copy link and print card functionality
- Add Share Bot button to bot Details page

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

LittleShop/Areas/Admin/Controllers/BotsController.cs

@@ -350,6 +350,23 @@ public class BotsController : Controller
         return RedirectToAction(nameof(Details), new { id });
     }
 
+    // GET: Admin/Bots/ShareCard/5
+    public async Task<IActionResult> ShareCard(Guid id)
+    {
+        var bot = await _botService.GetBotByIdAsync(id);
+        if (bot == null)
+            return NotFound();
+
+        // Build the tg.me link
+        var telegramLink = !string.IsNullOrEmpty(bot.PlatformUsername)
+            ? $"https://t.me/{bot.PlatformUsername}"
+            : null;
+
+        ViewData["TelegramLink"] = telegramLink;
+
+        return View(bot);
+    }
+
     private string GenerateBotFatherCommands(BotWizardDto dto)
     {
         var commands = new List<string>