Add HiFi API instance health check to Settings

New "Check All Instances" button in Settings > Downloads > HiFi
shows each configured instance with color-coded status: green for
fully working (can download), orange for search-only (downloads
fail), red for offline/SSL error/timeout. Helps users understand
why HiFi downloads aren't working when community instances go down.

web_server.py

@@ -31226,6 +31226,47 @@ def hifi_status():
         return jsonify({"available": False, "error": str(e)})
 
 
+@app.route('/api/hifi/instances', methods=['GET'])
+def hifi_instances():
+    """Check availability of all HiFi API instances."""
+    import requests as req
+    try:
+        hifi = soulseek_client.hifi
+        instances = list(hifi._instances)
+        results = []
+        for url in instances:
+            entry = {'url': url, 'status': 'unknown', 'version': None, 'can_search': False, 'can_download': False}
+            try:
+                # Check root for version
+                r = req.get(f'{url}/', timeout=5, headers={'Accept': 'application/json'})
+                if r.ok:
+                    data = r.json()
+                    entry['version'] = data.get('version')
+                    entry['status'] = 'online'
+                    # Check search
+                    sr = req.get(f'{url}/search', params={'s': 'test', 'limit': 1}, timeout=5)
+                    entry['can_search'] = sr.ok
+                    # Check track (download capability)
+                    tr = req.get(f'{url}/track', params={'id': '1550546', 'quality': 'LOSSLESS'}, timeout=5)
+                    entry['can_download'] = tr.ok
+                    if not tr.ok:
+                        entry['download_error'] = f'HTTP {tr.status_code}'
+                else:
+                    entry['status'] = f'error (HTTP {r.status_code})'
+            except req.exceptions.SSLError:
+                entry['status'] = 'ssl_error'
+            except req.exceptions.ConnectTimeout:
+                entry['status'] = 'timeout'
+            except req.exceptions.ConnectionError:
+                entry['status'] = 'offline'
+            except Exception as e:
+                entry['status'] = f'error ({type(e).__name__})'
+            results.append(entry)
+        return jsonify({'instances': results, 'active': hifi._get_instance()})
+    except Exception as e:
+        return jsonify({'error': str(e)}), 500
+
+
 # ===================================================================
 # DEEZER DOWNLOAD ENDPOINTS
 # ===================================================================

webui/index.html

@@ -4825,6 +4825,11 @@
                                             Free lossless downloads via community-run hifi-api instances. No authentication or subscription needed.
                                         </div>
                                     </div>
+                                    <div class="form-group">
+                                        <label>API Instances:</label>
+                                        <button class="test-button" onclick="checkHiFiInstances()" id="hifi-instances-check-btn" style="margin-bottom: 8px;">Check All Instances</button>
+                                        <div id="hifi-instances-panel" style="display: none;"></div>
+                                    </div>
                                 </div>
 
                                 <!-- Deezer Download Settings (shown only when deezer_dl mode is selected) -->

webui/static/script.js

@@ -7738,6 +7738,45 @@ async function testHiFiConnection() {
     }
 }
 
+async function checkHiFiInstances() {
+    const panel = document.getElementById('hifi-instances-panel');
+    const btn = document.getElementById('hifi-instances-check-btn');
+    if (!panel) return;
+    panel.style.display = 'block';
+    panel.innerHTML = '<div style="color: rgba(255,255,255,0.4); font-size: 0.85em; padding: 8px 0;">Checking instances...</div>';
+    if (btn) { btn.disabled = true; btn.textContent = 'Checking...'; }
+    try {
+        const resp = await fetch('/api/hifi/instances');
+        const data = await resp.json();
+        if (!data.instances || data.instances.length === 0) {
+            panel.innerHTML = '<div style="color: #ff9800; font-size: 0.85em;">No instances configured.</div>';
+            return;
+        }
+        const _statusIcon = (inst) => {
+            if (inst.can_download) return '<span style="color:#4caf50">● Download</span>';
+            if (inst.can_search) return '<span style="color:#ff9800">● Search only</span>';
+            if (inst.status === 'online') return '<span style="color:#ff9800">● Online (limited)</span>';
+            if (inst.status === 'ssl_error') return '<span style="color:#f44336">● SSL error</span>';
+            if (inst.status === 'timeout') return '<span style="color:#f44336">● Timeout</span>';
+            if (inst.status === 'offline') return '<span style="color:#f44336">● Offline</span>';
+            return `<span style="color:#f44336">● ${escapeHtml(inst.status)}</span>`;
+        };
+        panel.innerHTML = data.instances.map(inst => {
+            const isActive = inst.url === data.active;
+            const ver = inst.version ? ` v${inst.version}` : '';
+            const activeTag = isActive ? ' <span style="color:rgb(var(--accent-rgb));font-weight:600;font-size:0.75em;">(ACTIVE)</span>' : '';
+            return `<div style="display:flex;justify-content:space-between;align-items:center;padding:5px 0;border-bottom:1px solid rgba(255,255,255,0.04);font-size:0.82em;">
+                <span style="color:rgba(255,255,255,0.6);font-family:monospace;overflow:hidden;text-overflow:ellipsis;">${escapeHtml(inst.url)}${ver}${activeTag}</span>
+                <span style="flex-shrink:0;margin-left:12px;">${_statusIcon(inst)}</span>
+            </div>`;
+        }).join('');
+    } catch (e) {
+        panel.innerHTML = `<div style="color:#f44336;font-size:0.85em;">Error checking instances: ${escapeHtml(e.message)}</div>`;
+    } finally {
+        if (btn) { btn.disabled = false; btn.textContent = 'Check All Instances'; }
+    }
+}
+
 async function testDeezerDownloadConnection() {
     const statusEl = document.getElementById('deezer-download-status');
     if (!statusEl) return;