feat: analysis providers, settings UI, song search, WAV duration fix

- Multi-provider AI analysis (Anthropic, OpenAI, Ollama, Algorithmic)
- server-only guards on all provider files; client bundle fix
- /settings page with provider status, Ollama model picker, preferences
- Song search box on /analyze replacing raw MBID input (debounced, keyboard nav)
- Auto-register song via MusicBrainz on POST /api/tracks (no more 404)
- Fix WAV duration bug: last section songEnd was double-counting elapsed time
- Registry sync comment updated for self-hosted HTTPS git servers

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

components/settings/ProviderStatus.tsx

@@ -0,0 +1,114 @@
+"use client";
+
+import { useState } from "react";
+import type { ProviderInfo } from "@/lib/analysis/providers";
+
+interface ProviderStatusProps {
+  provider: ProviderInfo;
+  selectedOllamaModel?: string;
+  isDefault: boolean;
+  onSetDefault: (id: string) => void;
+}
+
+const TYPE_LABELS: Record<ProviderInfo["type"], string> = {
+  "cloud-ai": "Cloud AI",
+  "local-ai": "Local AI",
+  "algorithmic": "No AI",
+};
+
+export default function ProviderStatus({
+  provider,
+  selectedOllamaModel,
+  isDefault,
+  onSetDefault,
+}: ProviderStatusProps) {
+  const [testStatus, setTestStatus] = useState<"idle" | "testing" | "ok" | "error">("idle");
+  const [testError, setTestError] = useState("");
+
+  async function handleTest() {
+    setTestStatus("testing");
+    setTestError("");
+    try {
+      const res = await fetch("/api/analyze/test", {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({
+          provider: provider.id,
+          ollamaModel: provider.id === "ollama" ? selectedOllamaModel : undefined,
+        }),
+      });
+      const data = await res.json() as { ok: boolean; error?: string };
+      if (data.ok) {
+        setTestStatus("ok");
+      } else {
+        setTestStatus("error");
+        setTestError(data.error ?? "Unknown error");
+      }
+    } catch (err) {
+      setTestStatus("error");
+      setTestError(err instanceof Error ? err.message : String(err));
+    }
+  }
+
+  return (
+    <div className="rounded-lg border border-zinc-800 bg-zinc-900/60 p-4">
+      <div className="flex items-start justify-between gap-3">
+        <div className="flex-1 min-w-0">
+          <div className="flex items-center gap-2 flex-wrap">
+            <span className="font-medium text-zinc-200">{provider.label}</span>
+            <span className="rounded px-1.5 py-0.5 text-xs bg-zinc-800 text-zinc-400">
+              {TYPE_LABELS[provider.type]}
+            </span>
+            {provider.available ? (
+              <span className="rounded px-1.5 py-0.5 text-xs bg-green-900/50 text-green-400">
+                Available
+              </span>
+            ) : (
+              <span className="rounded px-1.5 py-0.5 text-xs bg-zinc-800 text-zinc-500">
+                Unavailable
+              </span>
+            )}
+            {isDefault && (
+              <span className="rounded px-1.5 py-0.5 text-xs bg-blue-900/50 text-blue-400">
+                Default
+              </span>
+            )}
+          </div>
+          {!provider.available && provider.unavailableReason && (
+            <p className="mt-1 text-xs text-zinc-600">{provider.unavailableReason}</p>
+          )}
+          {provider.id === "ollama" && provider.available && provider.ollamaBaseUrl && (
+            <p className="mt-1 text-xs text-zinc-600 font-mono">{provider.ollamaBaseUrl}</p>
+          )}
+        </div>
+
+        {provider.available && (
+          <div className="flex items-center gap-2 shrink-0">
+            {!isDefault && (
+              <button
+                onClick={() => onSetDefault(provider.id)}
+                className="text-xs text-zinc-500 hover:text-zinc-300 underline"
+              >
+                Set as default
+              </button>
+            )}
+            <button
+              onClick={handleTest}
+              disabled={testStatus === "testing"}
+              className="rounded px-3 py-1 text-xs font-medium border border-zinc-700 text-zinc-300 hover:border-zinc-500 hover:text-zinc-100 transition-colors disabled:opacity-50"
+            >
+              {testStatus === "testing" ? "Testing…" : "Test"}
+            </button>
+          </div>
+        )}
+      </div>
+
+      {testStatus === "ok" && (
+        <p className="mt-2 text-xs text-green-400">✓ Working</p>
+      )}
+      {testStatus === "error" && (
+        <p className="mt-2 text-xs text-red-400">✗ {testError}</p>
+      )}
+    </div>
+  );
+}