feat: add public image proxy and wire TrackCard cover art to api/image/{entryKey}

DeepDrftPublic.Client/Controls/TrackCard.razor

@@ -12,7 +12,7 @@
         <a href="@trackHref" class="deepdrft-track-card-link">
             @if (!string.IsNullOrEmpty(TrackModel?.ImagePath))
             {
-                <div class="deepdrft-track-card-bg" style="background-image: url('@TrackModel.ImagePath');">
+                <div class="deepdrft-track-card-bg" style="background-image: url('api/image/@Uri.EscapeDataString(TrackModel.ImagePath)');">
                 </div>
             }
             else
@@ -23,7 +23,7 @@
     }
     else if (!string.IsNullOrEmpty(TrackModel?.ImagePath))
     {
-        <div class="deepdrft-track-card-bg" style="background-image: url('@TrackModel.ImagePath');">
+        <div class="deepdrft-track-card-bg" style="background-image: url('api/image/@Uri.EscapeDataString(TrackModel.ImagePath)');">
         </div>
     }
     else

DeepDrftPublic/Controllers/ImageProxyController.cs

@@ -0,0 +1,63 @@
+using Microsoft.AspNetCore.Mvc;
+
+namespace DeepDrftPublic.Controllers;
+
+/// <summary>
+/// Proxies public image API calls to DeepDrftAPI so the browser never makes
+/// cross-origin requests. Mirrors <see cref="TrackProxyController"/>: the WASM
+/// client issues relative <c>api/image/{entryKey}</c> requests against this host,
+/// which forwards them upstream. SSR prerender calls DeepDrftAPI directly via the
+/// same named client — no proxy hop needed on the server side.
+/// </summary>
+[ApiController]
+[Route("api/image")]
+public class ImageProxyController : ControllerBase
+{
+    private readonly HttpClient _upstream;
+    private readonly ILogger<ImageProxyController> _logger;
+
+    public ImageProxyController(IHttpClientFactory httpClientFactory, ILogger<ImageProxyController> logger)
+    {
+        _upstream = httpClientFactory.CreateClient("DeepDrft.API");
+        _logger = logger;
+    }
+
+    /// <summary>Proxies image binary streaming by vault entry key from DeepDrftAPI.</summary>
+    [HttpGet("{entryKey}")]
+    public async Task<ActionResult> GetImage(string entryKey, CancellationToken ct = default)
+    {
+        _logger.LogInformation("Proxying image {EntryKey}", entryKey);
+
+        var path = $"api/image/{Uri.EscapeDataString(entryKey)}";
+
+        HttpResponseMessage upstream;
+        try
+        {
+            upstream = await _upstream.GetAsync(path, HttpCompletionOption.ResponseHeadersRead, ct);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Upstream call to DeepDrftAPI image/{EntryKey} failed", entryKey);
+            return StatusCode(502, "Upstream unavailable");
+        }
+
+        if (!upstream.IsSuccessStatusCode)
+        {
+            upstream.Dispose();
+            _logger.LogWarning("DeepDrftAPI image/{EntryKey} returned {Status}", entryKey, (int)upstream.StatusCode);
+            return StatusCode((int)upstream.StatusCode);
+        }
+
+        // Do NOT dispose upstream here — File() takes ownership of the response stream
+        // and disposes it after the body is sent.
+        var contentType = upstream.Content.Headers.ContentType?.ToString() ?? "application/octet-stream";
+        var contentLength = upstream.Content.Headers.ContentLength;
+
+        if (contentLength.HasValue)
+            Response.ContentLength = contentLength.Value;
+
+        var stream = await upstream.Content.ReadAsStreamAsync(ct);
+        HttpContext.Response.RegisterForDispose(upstream);
+        return File(stream, contentType, enableRangeProcessing: false);
+    }
+}