diff --git a/package.json b/package.json
index 0ecb646..94b50f0 100644
--- a/package.json
+++ b/package.json
@@ -33,6 +33,8 @@
     "build": "tsc && vite build",
     "check:i18n": "vitest run src/i18n/resources.test.ts",
     "check:updates": "node scripts/check-updates.js",
+    "smoke:torrent": "node scripts/smoke-torrent.js",
+    "smoke:torrent:failure-paths": "node scripts/smoke-torrent.js --failure-paths",
     "verify:macos-signing": "node scripts/verify-macos-signing.js",
     "preview": "vite preview",
     "tauri": "tauri",
diff --git a/scripts/smoke-torrent.js b/scripts/smoke-torrent.js
new file mode 100644
index 0000000..72ed83e
--- /dev/null
+++ b/scripts/smoke-torrent.js
@@ -0,0 +1,715 @@
+#!/usr/bin/env node
+
+import crypto from 'node:crypto';
+import fs from 'node:fs';
+import http from 'node:http';
+import net from 'node:net';
+import os from 'node:os';
+import path from 'node:path';
+import { spawn } from 'node:child_process';
+import { fileURLToPath } from 'node:url';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+const repoRoot = path.resolve(__dirname, '..');
+
+function argumentValue(name) {
+  const index = process.argv.indexOf(name);
+  return index >= 0 ? process.argv[index + 1] : undefined;
+}
+
+if (process.argv.includes('--help')) {
+  console.log('Usage: node scripts/smoke-torrent.js [--binary PATH] [--failure-paths] [--keep-temp]');
+  process.exit(0);
+}
+
+const keepTemp = process.argv.includes('--keep-temp');
+const runFailurePaths = process.argv.includes('--failure-paths');
+const arch = { x64: 'x86_64', arm64: 'aarch64' }[os.arch()];
+const platform = {
+  darwin: 'apple-darwin',
+  linux: 'unknown-linux-gnu',
+  win32: 'pc-windows-msvc',
+}[os.platform()];
+if (!arch || !platform) {
+  throw new Error(`Unsupported host: ${os.arch()} / ${os.platform()}`);
+}
+const targetTriple = `${arch}-${platform}`;
+const executableName = `aria2c-${targetTriple}${os.platform() === 'win32' ? '.exe' : ''}`;
+const binaryPath = path.resolve(
+  argumentValue('--binary') || path.join(repoRoot, 'src-tauri', 'binaries', executableName),
+);
+
+const sleep = milliseconds => new Promise(resolve => setTimeout(resolve, milliseconds));
+const activeDaemons = new Set();
+let runtimeTempRoot;
+let runtimeTracker;
+let cleanupPromise;
+let signalTerminationRequested = false;
+
+function childExited(child) {
+  return child.exitCode !== null || child.signalCode !== null;
+}
+
+async function findAvailablePort() {
+  const server = net.createServer();
+  await new Promise((resolve, reject) => {
+    server.once('error', reject);
+    server.listen({ host: '127.0.0.1', port: 0 }, resolve);
+  });
+  const address = server.address();
+  const port = address && typeof address !== 'string' ? address.port : null;
+  await new Promise(resolve => server.close(resolve));
+  if (!port) throw new Error('Could not reserve a local port');
+  return port;
+}
+
+function bencode(value) {
+  if (Buffer.isBuffer(value)) {
+    return Buffer.concat([Buffer.from(`${value.length}:`), value]);
+  }
+  if (typeof value === 'string') return bencode(Buffer.from(value));
+  if (typeof value === 'number' && Number.isInteger(value)) {
+    return Buffer.from(`i${value}e`);
+  }
+  if (Array.isArray(value)) {
+    return Buffer.concat([Buffer.from('l'), ...value.map(bencode), Buffer.from('e')]);
+  }
+  if (value instanceof Map || (value && typeof value === 'object')) {
+    const entries = value instanceof Map ? [...value.entries()] : Object.entries(value);
+    entries.sort(([left], [right]) => Buffer.compare(Buffer.from(left), Buffer.from(right)));
+    return Buffer.concat([
+      Buffer.from('d'),
+      ...entries.flatMap(([key, child]) => [bencode(String(key)), bencode(child)]),
+      Buffer.from('e'),
+    ]);
+  }
+  throw new Error(`Unsupported bencode value: ${typeof value}`);
+}
+
+function decodeBencode(bytes) {
+  let position = 0;
+  const parse = () => {
+    const marker = bytes[position];
+    if (marker === 0x69) {
+      position += 1;
+      const end = bytes.indexOf(0x65, position);
+      if (end < 0) throw new Error('Malformed integer in saved torrent');
+      const value = Number(bytes.subarray(position, end).toString('ascii'));
+      position = end + 1;
+      return value;
+    }
+    if (marker === 0x6c) {
+      position += 1;
+      const values = [];
+      while (bytes[position] !== 0x65) values.push(parse());
+      position += 1;
+      return values;
+    }
+    if (marker === 0x64) {
+      position += 1;
+      const values = new Map();
+      while (bytes[position] !== 0x65) {
+        const key = parse();
+        if (!Buffer.isBuffer(key)) throw new Error('Malformed dictionary key in saved torrent');
+        values.set(key.toString('utf8'), parse());
+      }
+      position += 1;
+      return values;
+    }
+    if (marker >= 0x30 && marker <= 0x39) {
+      const separator = bytes.indexOf(0x3a, position);
+      if (separator < 0) throw new Error('Malformed byte string in saved torrent');
+      const length = Number(bytes.subarray(position, separator).toString('ascii'));
+      position = separator + 1;
+      const value = bytes.subarray(position, position + length);
+      if (value.length !== length) throw new Error('Truncated byte string in saved torrent');
+      position += length;
+      return value;
+    }
+    throw new Error(`Unexpected bencode marker ${String.fromCharCode(marker || 0)}`);
+  };
+  const value = parse();
+  if (position !== bytes.length) throw new Error('Saved torrent contains trailing data');
+  return value;
+}
+
+function sha1(value) {
+  return crypto.createHash('sha1').update(value).digest();
+}
+
+function createRuntimeTorrent(trackerUrl) {
+  const name = 'firelink-torrent-runtime';
+  const pieceLength = 16 * 1024;
+  const files = [
+    {
+      path: 'selected.bin',
+      data: Buffer.alloc(256 * 1024, 0x53),
+    },
+    {
+      path: 'skipped.bin',
+      data: Buffer.from('this file must not be selected\n'),
+    },
+  ];
+  const piecesSource = Buffer.concat(files.map(file => file.data));
+  const pieces = [];
+  for (let offset = 0; offset < piecesSource.length; offset += pieceLength) {
+    pieces.push(sha1(piecesSource.subarray(offset, offset + pieceLength)));
+  }
+  const info = new Map([
+    ['files', files.map(file => new Map([
+      ['length', file.data.length],
+      ['path', [file.path]],
+    ]))],
+    ['name', name],
+    ['piece length', pieceLength],
+    ['pieces', Buffer.concat(pieces)],
+  ]);
+  const torrent = new Map([
+    ['announce', trackerUrl],
+    ['info', info],
+  ]);
+  const bytes = bencode(torrent);
+  const infoHash = sha1(bencode(info)).toString('hex');
+  return { bytes, infoHash, name, files };
+}
+
+function startTracker(seederPort) {
+  let activeSeederPort = seederPort;
+  const server = http.createServer((request, response) => {
+    if (!request.url || new URL(request.url, 'http://127.0.0.1').pathname !== '/announce') {
+      response.writeHead(404).end();
+      return;
+    }
+    const peer = Buffer.alloc(6);
+    peer[0] = 127;
+    peer[1] = 0;
+    peer[2] = 0;
+    peer[3] = 1;
+    peer.writeUInt16BE(activeSeederPort, 4);
+    const body = bencode(new Map([
+      ['complete', 1],
+      ['incomplete', 0],
+      ['interval', 2],
+      ['min interval', 1],
+      ['peers', peer],
+    ]));
+    response.writeHead(200, {
+      'Content-Length': body.length,
+      'Content-Type': 'text/plain',
+    });
+    response.end(body);
+  });
+  return {
+    server,
+    setSeederPort(port) {
+      activeSeederPort = port;
+    },
+  };
+}
+
+async function listen(server) {
+  await new Promise((resolve, reject) => {
+    server.once('error', reject);
+    server.listen({ host: '127.0.0.1', port: 0 }, resolve);
+  });
+  const address = server.address();
+  if (!address || typeof address === 'string') throw new Error('Could not determine local server port');
+  return address.port;
+}
+
+function daemonEnvironment() {
+  const libraries = path.join(path.dirname(binaryPath), 'aria2-libs');
+  return fs.existsSync(libraries)
+    ? { ...process.env, OPENSSL_MODULES: libraries }
+    : process.env;
+}
+
+async function rpc(port, secret, method, params = []) {
+  const response = await fetch(`http://127.0.0.1:${port}/jsonrpc`, {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify({
+      jsonrpc: '2.0',
+      id: `firelink-torrent-${Date.now()}`,
+      method,
+      params: [`token:${secret}`, ...params],
+    }),
+    signal: AbortSignal.timeout(3000),
+  });
+  const body = await response.json();
+  if (body.error) throw new Error(`${method}: ${JSON.stringify(body.error)}`);
+  if (!Object.hasOwn(body, 'result')) throw new Error(`${method}: response has no result`);
+  return body.result;
+}
+
+async function waitFor(description, check, timeoutMs = 15000) {
+  const deadline = Date.now() + timeoutMs;
+  let lastError;
+  while (Date.now() < deadline) {
+    try {
+      const result = await check();
+      if (result) return result;
+    } catch (error) {
+      lastError = error;
+    }
+    await sleep(100);
+  }
+  throw new Error(`Timed out waiting for ${description}${lastError ? `: ${lastError.message}` : ''}`);
+}
+
+async function startDaemon({ name, rpcPort, listenPort, directory, extraArgs = [] }) {
+  const maxAttempts = 3;
+  let lastError;
+  for (let attempt = 0; attempt < maxAttempts; attempt += 1) {
+    const selectedRpcPort = attempt === 0 ? rpcPort : await findAvailablePort();
+    const selectedListenPort = listenPort === undefined
+      ? undefined
+      : attempt === 0 ? listenPort : await findAvailablePort();
+    const secret = `firelink-${name}-${crypto.randomUUID()}`;
+    const stderr = [];
+    const child = spawn(binaryPath, [
+      '--enable-rpc=true',
+      `--rpc-listen-port=${selectedRpcPort}`,
+      '--rpc-listen-all=false',
+      `--rpc-secret=${secret}`,
+      `--dir=${directory}`,
+      '--file-allocation=none',
+      '--enable-dht=false',
+      '--enable-peer-exchange=false',
+      '--bt-enable-lpd=false',
+      '--console-log-level=error',
+      '--quiet=true',
+      ...(selectedListenPort ? [`--listen-port=${selectedListenPort}`] : []),
+      ...extraArgs,
+    ], {
+      env: daemonEnvironment(),
+      stdio: ['ignore', 'ignore', 'pipe'],
+    });
+    child.stderr.on('data', chunk => stderr.push(chunk.toString()));
+    let exit;
+    child.once('exit', (code, signal) => { exit = { code, signal }; });
+    child.once('error', error => { exit = { error }; });
+    const daemon = {
+      child,
+      secret,
+      stderr,
+      rpcPort: selectedRpcPort,
+      listenPort: selectedListenPort,
+    };
+    activeDaemons.add(daemon);
+    try {
+      await waitFor(`${name} Aria2 RPC`, async () => {
+        if (exit) throw new Error(`${name} exited: ${exit.error?.message || `${exit.code}/${exit.signal}`}`);
+        try {
+          await rpc(selectedRpcPort, secret, 'aria2.getVersion');
+          return true;
+        } catch {
+          return false;
+        }
+      }, 10000);
+      return daemon;
+    } catch (error) {
+      lastError = error;
+      const detail = `${error.message}\n${stderr.join('')}`;
+      await stopDaemon(daemon);
+      if (!/address already in use|failed to bind|could not bind|listen failed/i.test(detail)) {
+        throw error;
+      }
+    }
+  }
+  throw lastError || new Error(`Could not start ${name} Aria2 daemon`);
+}
+
+async function stopDaemon(daemon) {
+  const child = daemon?.child;
+  if (!child) return;
+  try {
+    if (!childExited(child)) {
+      try {
+        await rpc(daemon.rpcPort, daemon.secret, 'aria2.shutdown');
+      } catch {
+        // The process may already have exited during cleanup.
+      }
+    }
+    if (!await waitForChildExit(child, 3000)) {
+      child.kill('SIGTERM');
+      if (!await waitForChildExit(child, 3000) && process.platform !== 'win32') {
+        child.kill('SIGKILL');
+        await waitForChildExit(child, 1000);
+      }
+    }
+  } finally {
+    activeDaemons.delete(daemon);
+  }
+}
+
+async function closeServer(server) {
+  if (!server || !server.listening) return;
+  await new Promise(resolve => server.close(() => resolve()));
+}
+
+async function cleanupRuntime() {
+  if (cleanupPromise) return cleanupPromise;
+  cleanupPromise = (async () => {
+    for (const daemon of [...activeDaemons].reverse()) {
+      try {
+        await stopDaemon(daemon);
+      } catch (error) {
+        console.error(`[WARN] failed to stop Aria2 daemon: ${error.message}`);
+      }
+    }
+    if (runtimeTracker) {
+      const tracker = runtimeTracker;
+      runtimeTracker = undefined;
+      await closeServer(tracker.server);
+    }
+    if (runtimeTempRoot) {
+      const tempRoot = runtimeTempRoot;
+      runtimeTempRoot = undefined;
+      if (keepTemp) console.log(`[INFO] retained smoke-test directory: ${tempRoot}`);
+      else fs.rmSync(tempRoot, { recursive: true, force: true });
+    }
+  })();
+  return cleanupPromise;
+}
+
+async function tellStatus(daemon, gid) {
+  return rpc(daemon.rpcPort, daemon.secret, 'aria2.tellStatus', [gid, [
+    'status',
+    'errorCode',
+    'errorMessage',
+    'completedLength',
+    'totalLength',
+    'files',
+  ]]);
+}
+
+async function waitForTerminal(daemon, gid, timeoutMs = 30000) {
+  let lastStatus;
+  try {
+    return await waitFor(`Aria2 transfer ${gid} to complete`, async () => {
+      lastStatus = await tellStatus(daemon, gid);
+      if (lastStatus.status === 'complete') return lastStatus;
+      if (lastStatus.status === 'error' || lastStatus.status === 'removed') {
+        throw new Error(`transfer ended ${lastStatus.status}: ${lastStatus.errorCode || ''} ${lastStatus.errorMessage || ''}`);
+      }
+      return false;
+    }, timeoutMs);
+  } catch (error) {
+    const stderr = daemon.stderr?.join('').trim();
+    throw new Error(`${error.message}; last status ${JSON.stringify(lastStatus)}${stderr ? `; stderr ${stderr}` : ''}`);
+  }
+}
+
+async function waitForStatus(daemon, gid, expected, timeoutMs = 10000) {
+  return waitFor(`Aria2 transfer ${gid} to become ${expected}`, async () => {
+    const status = await tellStatus(daemon, gid);
+    if (status.status === expected) return status;
+    if (status.status === 'error' || status.status === 'removed') {
+      throw new Error(`transfer ended ${status.status}: ${status.errorCode || ''} ${status.errorMessage || ''}`);
+    }
+    return false;
+  }, timeoutMs);
+}
+
+async function waitForDataComplete(daemon, gid, timeoutMs = 30000) {
+  let lastStatus;
+  try {
+    return await waitFor(`Aria2 transfer ${gid} data to complete`, async () => {
+      lastStatus = await tellStatus(daemon, gid);
+      if (lastStatus.status === 'error' || lastStatus.status === 'removed') {
+        throw new Error(`transfer ended ${lastStatus.status}: ${lastStatus.errorCode || ''} ${lastStatus.errorMessage || ''}`);
+      }
+      return Number(lastStatus.completedLength) === Number(lastStatus.totalLength) ? lastStatus : false;
+    }, timeoutMs);
+  } catch (error) {
+    const stderr = daemon.stderr?.join('').trim();
+    throw new Error(`${error.message}; last status ${JSON.stringify(lastStatus)}${stderr ? `; stderr ${stderr}` : ''}`);
+  }
+}
+
+async function waitForRemoved(daemon, gid) {
+  let lastStatus;
+  try {
+    return await waitFor(`Aria2 transfer ${gid} to be removed`, async () => {
+      try {
+        lastStatus = await tellStatus(daemon, gid);
+        return lastStatus.status === 'removed' ? lastStatus : false;
+      } catch (error) {
+        return /not found|no such download/i.test(error.message) ? true : false;
+      }
+    }, 10000);
+  } catch (error) {
+    throw new Error(`${error.message}; last status ${JSON.stringify(lastStatus)}`);
+  }
+}
+
+async function forceRemoveIfPresent(daemon, gid) {
+  try {
+    await rpc(daemon.rpcPort, daemon.secret, 'aria2.forceRemove', [gid]);
+    return true;
+  } catch (error) {
+    if (/not found|no such download|active download not found/i.test(error.message)) return false;
+    throw error;
+  }
+}
+
+async function waitForChildExit(child, timeoutMs = 5000) {
+  if (childExited(child)) return true;
+  return new Promise(resolve => {
+    let settled = false;
+    let timer;
+    let onExit;
+    const finish = result => {
+      if (settled) return;
+      settled = true;
+      clearTimeout(timer);
+      child.off('exit', onExit);
+      resolve(result);
+    };
+    timer = setTimeout(() => {
+      finish(false);
+    }, timeoutMs);
+    onExit = () => finish(true);
+    child.once('exit', onExit);
+    if (childExited(child)) finish(true);
+  });
+}
+
+function assert(condition, message) {
+  if (!condition) throw new Error(message);
+}
+
+async function runFailurePathChecks({ client, tempRoot }) {
+  const failureDir = path.join(tempRoot, 'failure');
+  fs.mkdirSync(failureDir, { recursive: true });
+  const unavailablePort = await findAvailablePort();
+  const unavailableInfoHash = 'deadbeefdeadbeefdeadbeefdeadbeefdeadbeef';
+  const unavailableMagnet = `magnet:?xt=urn:btih:${unavailableInfoHash}&dn=unavailable-firelink-fixture&tr=${encodeURIComponent(`http://127.0.0.1:${unavailablePort}/announce`)}`;
+  const failureGid = await rpc(client.rpcPort, client.secret, 'aria2.addUri', [[unavailableMagnet], {
+    dir: failureDir,
+    'bt-metadata-only': 'true',
+    'bt-save-metadata': 'true',
+    'max-tries': '1',
+    'retry-wait': '1',
+    'connect-timeout': '1',
+    'bt-tracker-connect-timeout': '1',
+    timeout: '2',
+    'auto-file-renaming': 'false',
+  }]);
+  let lastStatus;
+  const deadline = Date.now() + 8000;
+  while (Date.now() < deadline) {
+    try {
+      lastStatus = await tellStatus(client, failureGid);
+      if (lastStatus.status === 'error' || lastStatus.status === 'complete') break;
+    } catch {
+      break;
+    }
+    await sleep(100);
+  }
+  const failureRemoved = await forceRemoveIfPresent(client, failureGid);
+  if (failureRemoved) await waitForRemoved(client, failureGid);
+  const savedFailureMetadata = fs.readdirSync(failureDir)
+    .filter(file => file.toLowerCase().endsWith('.torrent'));
+  assert(savedFailureMetadata.length === 0, 'unavailable tracker produced metadata unexpectedly');
+  assert(lastStatus?.status !== 'complete', 'unavailable tracker completed a metadata probe unexpectedly');
+  console.log(`[OK] unavailable tracker was cleaned up without metadata (${lastStatus?.status || 'gone'})`);
+
+  const exitDir = path.join(tempRoot, 'daemon-exit');
+  fs.mkdirSync(exitDir, { recursive: true });
+  const exitRpcPort = await findAvailablePort();
+  const exitDaemon = await startDaemon({
+    name: 'exit',
+    rpcPort: exitRpcPort,
+    listenPort: await findAvailablePort(),
+    directory: exitDir,
+    extraArgs: ['--seed-time=0'],
+  });
+  const exitGid = await rpc(exitDaemon.rpcPort, exitDaemon.secret, 'aria2.addUri', [[unavailableMagnet], {
+    dir: exitDir,
+    'bt-metadata-only': 'true',
+    'bt-save-metadata': 'true',
+    'max-tries': '1',
+    'connect-timeout': '1',
+    'bt-tracker-connect-timeout': '1',
+    timeout: '15',
+  }]);
+  assert(exitGid, 'daemon-exit probe did not return a GID');
+  exitDaemon.child.kill('SIGTERM');
+  assert(await waitForChildExit(exitDaemon.child), 'Aria2 daemon did not exit after termination');
+  assert(
+    !fs.readdirSync(exitDir).some(file => file.toLowerCase().endsWith('.torrent')),
+    'daemon exit left saved metadata in the probe directory',
+  );
+  console.log('[OK] daemon termination left no saved probe metadata');
+}
+
+async function main() {
+  if (!fs.existsSync(binaryPath)) {
+    throw new Error(`aria2c binary not found: ${binaryPath}`);
+  }
+
+  runtimeTempRoot = fs.mkdtempSync(path.join(os.tmpdir(), 'firelink-torrent-smoke-'));
+  try {
+    const tempRoot = runtimeTempRoot;
+    const seedParent = path.join(tempRoot, 'seed');
+    const seedRoot = path.join(seedParent, 'firelink-torrent-runtime');
+    const probeDir = path.join(tempRoot, 'probe');
+    const finalDir = path.join(tempRoot, 'final');
+    const cancelDir = path.join(tempRoot, 'cancel');
+    for (const directory of [seedRoot, probeDir, finalDir, cancelDir]) fs.mkdirSync(directory, { recursive: true });
+
+    const seederListenPort = await findAvailablePort();
+    const clientListenPort = await findAvailablePort();
+    runtimeTracker = startTracker(seederListenPort);
+    const trackerPort = await listen(runtimeTracker.server);
+    const torrent = createRuntimeTorrent(`http://127.0.0.1:${trackerPort}/announce`);
+    for (const file of torrent.files) fs.writeFileSync(path.join(seedRoot, file.path), file.data);
+    const magnet = `magnet:?xt=urn:btih:${torrent.infoHash}&dn=${encodeURIComponent(torrent.name)}&tr=${encodeURIComponent(`http://127.0.0.1:${trackerPort}/announce`)}`;
+    const indexOut = [
+      `1=${torrent.name}/selected.bin`,
+      `2=${torrent.name}/skipped.bin`,
+    ];
+    const seederRpcPort = await findAvailablePort();
+    const seeder = await startDaemon({
+      name: 'seeder',
+      rpcPort: seederRpcPort,
+      listenPort: seederListenPort,
+      directory: seedParent,
+      extraArgs: ['--seed-time=60', '--seed-ratio=0'],
+    });
+    runtimeTracker.setSeederPort(seeder.listenPort);
+    const seedGid = await rpc(seeder.rpcPort, seeder.secret, 'aria2.addTorrent', [
+      torrent.bytes.toString('base64'),
+      [],
+      {
+        dir: seedParent,
+        'seed-time': '60',
+        'seed-ratio': '0',
+        'allow-overwrite': 'true',
+        'check-integrity': 'true',
+      },
+    ]);
+    await waitForDataComplete(seeder, seedGid);
+    console.log(`[OK] local seeder completed ${seedGid}`);
+
+    const clientRpcPort = await findAvailablePort();
+    const client = await startDaemon({
+      name: 'client',
+      rpcPort: clientRpcPort,
+      listenPort: clientListenPort,
+      directory: probeDir,
+      extraArgs: ['--seed-time=0'],
+    });
+    const probeGid = await rpc(client.rpcPort, client.secret, 'aria2.addUri', [[magnet], {
+      dir: probeDir,
+      'bt-metadata-only': 'true',
+      'bt-save-metadata': 'true',
+      'max-tries': '3',
+      'retry-wait': '1',
+      'connect-timeout': '5',
+      timeout: '15',
+      'auto-file-renaming': 'false',
+    }]);
+    const probeStatus = await waitForTerminal(client, probeGid, 30000);
+    assert(probeStatus.status === 'complete', 'magnet metadata probe did not complete');
+    const savedTorrentPaths = fs.readdirSync(probeDir)
+      .filter(file => file.toLowerCase().endsWith('.torrent'))
+      .map(file => path.join(probeDir, file));
+    assert(savedTorrentPaths.length === 1, `expected one saved metadata file, found ${savedTorrentPaths.length}`);
+    const expectedMetadataPath = path.join(probeDir, `${torrent.infoHash}.torrent`);
+    assert(savedTorrentPaths[0] === expectedMetadataPath, `Aria2 saved metadata at an unexpected path: ${savedTorrentPaths[0]}`);
+    const savedTorrentBytes = fs.readFileSync(savedTorrentPaths[0]);
+    const savedTorrent = decodeBencode(savedTorrentBytes);
+    const savedInfo = savedTorrent instanceof Map ? savedTorrent.get('info') : undefined;
+    assert(savedInfo instanceof Map, 'saved metadata has no info dictionary');
+    assert(sha1(bencode(savedInfo)).toString('hex') === torrent.infoHash, 'saved metadata hash differs from magnet');
+    console.log(`[OK] magnet metadata resolved and hash matched ${torrent.infoHash}`);
+    const probeRemoved = await forceRemoveIfPresent(client, probeGid);
+    if (probeRemoved) await waitForRemoved(client, probeGid);
+    fs.rmSync(probeDir, { recursive: true, force: true });
+    fs.mkdirSync(probeDir, { recursive: true });
+    console.log('[OK] metadata probe was removed after resolution');
+
+    const finalGid = await rpc(client.rpcPort, client.secret, 'aria2.addTorrent', [
+      savedTorrentBytes.toString('base64'),
+      [],
+      {
+        dir: finalDir,
+        'select-file': '1',
+        'index-out': indexOut,
+        'max-download-limit': '32K',
+        'seed-time': '0',
+        'auto-file-renaming': 'false',
+      },
+    ]);
+    await waitForStatus(client, finalGid, 'active', 10000);
+    await rpc(client.rpcPort, client.secret, 'aria2.forcePause', [finalGid]);
+    await waitForStatus(client, finalGid, 'paused', 10000);
+    await rpc(client.rpcPort, client.secret, 'aria2.unpause', [finalGid]);
+    const finalStatus = await waitForTerminal(client, finalGid, 30000);
+    const selectedPath = path.join(finalDir, torrent.name, 'selected.bin');
+    const skippedPath = path.join(finalDir, torrent.name, 'skipped.bin');
+    assert(fs.existsSync(selectedPath), `selected torrent output is missing: ${selectedPath}`);
+    assert(fs.readFileSync(selectedPath).equals(torrent.files[0].data), 'selected torrent output content differs');
+    assert(!fs.existsSync(skippedPath), 'unselected torrent output was written');
+    const reportedFiles = await rpc(client.rpcPort, client.secret, 'aria2.getFiles', [finalGid]);
+    const reportedSelected = reportedFiles.find(file => file.path === selectedPath || file.path.endsWith('/selected.bin'));
+    assert(reportedSelected, `Aria2 ownership list did not report ${selectedPath}`);
+    assert(finalStatus.files?.some(file => file.path === selectedPath || file.path.endsWith('/selected.bin')), 'terminal status omitted selected output');
+    console.log('[OK] selected addTorrent output, pause/resume, and Aria2 file ownership passed');
+
+    const cancelGid = await rpc(client.rpcPort, client.secret, 'aria2.addTorrent', [
+      savedTorrentBytes.toString('base64'),
+      [],
+      {
+        dir: cancelDir,
+        'select-file': '1',
+        'index-out': indexOut,
+        'max-download-limit': '8K',
+        'seed-time': '0',
+        'auto-file-renaming': 'false',
+      },
+    ]);
+    await waitForStatus(client, cancelGid, 'active', 10000);
+    assert(await forceRemoveIfPresent(client, cancelGid), 'cancel/remove raced to a terminal state before forceRemove');
+    await waitForRemoved(client, cancelGid);
+    const canceledPath = path.join(cancelDir, torrent.name, 'selected.bin');
+    assert(
+      !fs.existsSync(canceledPath) || fs.statSync(canceledPath).size < torrent.files[0].data.length,
+      'canceled torrent produced a complete output',
+    );
+    console.log('[OK] cancel/remove stopped the second torrent before completion');
+
+    if (runFailurePaths) {
+      await runFailurePathChecks({ client, tempRoot });
+    }
+  } finally {
+    await cleanupRuntime();
+  }
+}
+
+function handleTerminationSignal(signal) {
+  if (signalTerminationRequested) return;
+  signalTerminationRequested = true;
+  void cleanupRuntime().then(() => {
+    process.exit(signal === 'SIGINT' ? 130 : 143);
+  }, error => {
+    console.error(`[FAIL] Torrent runtime smoke cleanup: ${error.message}`);
+    process.exit(signal === 'SIGINT' ? 130 : 143);
+  });
+}
+
+const onSigint = () => handleTerminationSignal('SIGINT');
+const onSigterm = () => handleTerminationSignal('SIGTERM');
+process.once('SIGINT', onSigint);
+process.once('SIGTERM', onSigterm);
+
+main().catch(error => {
+  console.error(`[FAIL] Torrent runtime smoke test: ${error.message}`);
+  process.exitCode = 1;
+}).finally(() => {
+  process.off('SIGINT', onSigint);
+  process.off('SIGTERM', onSigterm);
+});
diff --git a/src-tauri/tests/README.md b/src-tauri/tests/README.md
index dde7111..0d1ca99 100644
--- a/src-tauri/tests/README.md
+++ b/src-tauri/tests/README.md
@@ -23,3 +23,21 @@ cd src-tauri
 FIRELINK_LIVE_YOUTUBE_URL='https://www.youtube.com/watch?v=dQw4w9WgXcQ' \
   cargo test filters_live_youtube_metadata_from_env --lib -- --ignored --nocapture
 ```
+
+Run the real local Torrent runtime smoke test against the host bundled Aria2
+binary. It starts a local tracker and two Aria2 daemons, then covers magnet
+metadata resolution, saved-metadata hash validation, selected-file output,
+pause/resume, ownership reporting, and cancel/remove:
+
+```sh
+npm run smoke:torrent
+```
+
+Use `node scripts/smoke-torrent.js --binary /path/to/aria2c` when validating a
+packaged or target-specific Aria2 binary.
+
+Run the deterministic unavailable-tracker and Aria2-daemon-exit checks with:
+
+```sh
+npm run smoke:torrent:failure-paths
+```