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>

lib/analysis/providers/ollama.ts

@@ -0,0 +1,157 @@
+import 'server-only';
+
+import type { CTPDocument } from "@/lib/ctp/schema";
+import type { AnalysisInput, AnalysisProvider } from "@/lib/analysis/providers";
+import { SYSTEM_PROMPT } from "./anthropic";
+
+function getBaseUrl(): string {
+  return process.env.OLLAMA_BASE_URL ?? "http://localhost:11434";
+}
+
+// ─── Model list ───────────────────────────────────────────────────────────────
+
+interface OllamaTagsResponse {
+  models?: Array<{ name: string }>;
+}
+
+export async function getOllamaModels(): Promise<string[]> {
+  try {
+    const url = `${getBaseUrl()}/api/tags`;
+    const response = await fetch(url, { signal: AbortSignal.timeout(5000) });
+    if (!response.ok) return [];
+    const json = await response.json() as OllamaTagsResponse;
+    return (json.models ?? []).map((m) => m.name);
+  } catch {
+    return [];
+  }
+}
+
+// ─── Chat completions helper ──────────────────────────────────────────────────
+
+async function callOllama(model: string, userMessage: string): Promise<string> {
+  const baseUrl = getBaseUrl();
+  const response = await fetch(`${baseUrl}/v1/chat/completions`, {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify({
+      model,
+      messages: [
+        { role: "system", content: SYSTEM_PROMPT },
+        {
+          role: "user",
+          content:
+            userMessage +
+            "\n\nRespond with valid JSON only. Do not add any explanation or markdown. Your entire response must be a single valid JSON object matching the schema.",
+        },
+      ],
+      stream: false,
+    }),
+    signal: AbortSignal.timeout(120000), // 2-minute timeout for slow local models
+  });
+
+  if (!response.ok) {
+    const text = await response.text().catch(() => "");
+    throw new Error(`Ollama API error ${response.status}: ${text.slice(0, 200)}`);
+  }
+
+  const json = await response.json() as {
+    choices?: Array<{ message?: { content?: string } }>;
+  };
+
+  const content = json.choices?.[0]?.message?.content;
+  if (!content) {
+    throw new Error("Ollama did not return a message content");
+  }
+
+  return content;
+}
+
+// ─── Provider implementation ──────────────────────────────────────────────────
+
+export const ollamaProvider: AnalysisProvider = {
+  id: "ollama",
+  label: "Ollama",
+  type: "local-ai",
+
+  async isAvailable() {
+    const url = getBaseUrl();
+    try {
+      const response = await fetch(`${url}/api/tags`, {
+        signal: AbortSignal.timeout(5000),
+      });
+      if (response.ok) {
+        return { available: true };
+      }
+      return { available: false, reason: `Ollama not reachable at ${url}` };
+    } catch {
+      return { available: false, reason: `Ollama not reachable at ${url}` };
+    }
+  },
+
+  async generateCTP(input: AnalysisInput): Promise<CTPDocument> {
+    const { ollamaModel, bpm, duration, title, artist, mbid, contributed_by } = input;
+
+    if (!ollamaModel) {
+      throw new Error("ollamaModel is required for Ollama provider");
+    }
+
+    const approxBars = Math.round((duration * bpm) / 60 / 4);
+
+    const userMessage = `\
+Generate a CTP document for the following song:
+
+Title: ${title ?? "Unknown Title"}
+Artist: ${artist ?? "Unknown Artist"}
+MusicBrainz ID: ${mbid ?? "unknown"}
+Detected BPM: ${bpm}
+Duration: ${duration.toFixed(1)} seconds (~${approxBars} bars at 4/4)
+Contributed by: ${contributed_by}
+
+Create a plausible section layout for this song. If this is a well-known song, use your knowledge of its actual arrangement. If not, use a sensible generic structure.`;
+
+    // Attempt parse with one retry on failure
+    let content: string;
+    try {
+      content = await callOllama(ollamaModel, userMessage);
+    } catch (err) {
+      throw new Error(
+        `Ollama request failed: ${err instanceof Error ? err.message : String(err)}`
+      );
+    }
+
+    const tryParse = (raw: string): CTPDocument | null => {
+      // Strip markdown code fences if present
+      const stripped = raw.replace(/^```(?:json)?\s*/i, "").replace(/\s*```\s*$/, "").trim();
+      try {
+        const doc = JSON.parse(stripped) as CTPDocument;
+        if (!doc.metadata.created_at || doc.metadata.created_at.includes("placeholder")) {
+          doc.metadata.created_at = new Date().toISOString();
+        }
+        return doc;
+      } catch {
+        return null;
+      }
+    };
+
+    const firstAttempt = tryParse(content);
+    if (firstAttempt) return firstAttempt;
+
+    // Retry once
+    let retryContent: string;
+    try {
+      retryContent = await callOllama(ollamaModel, userMessage);
+    } catch (err) {
+      throw new Error(
+        `Ollama retry request failed: ${err instanceof Error ? err.message : String(err)}`
+      );
+    }
+
+    const secondAttempt = tryParse(retryContent);
+    if (secondAttempt) return secondAttempt;
+
+    throw new Error(
+      `Ollama (${ollamaModel}) returned a response that could not be parsed as a valid CTP document. ` +
+        `Response preview: ${content.slice(0, 200)}`
+    );
+  },
+};