Decouple stats daemon and preserve final mine OSD status

- Run `subminer stats -b` as a dedicated daemon process, independent from the overlay app
- Stop Anki progress spinner before showing final `✓`/`x` mine result so it is not overwritten
- Keep grammar/noise subtitle tokens hoverable while stripping annotation metadata

src/stats-daemon-control.test.ts

@@ -0,0 +1,158 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { createRunStatsDaemonControlHandler } from './stats-daemon-control';
+
+test('stats daemon control reuses live daemon and writes launcher response', async () => {
+  const calls: string[] = [];
+  const responses: Array<{ path: string; payload: { ok: boolean; url?: string; error?: string } }> =
+    [];
+  const handler = createRunStatsDaemonControlHandler({
+    statePath: '/tmp/stats-daemon.json',
+    readState: () => ({ pid: 4242, port: 5175, startedAtMs: 1 }),
+    removeState: () => {
+      calls.push('removeState');
+    },
+    isProcessAlive: (pid) => {
+      calls.push(`isProcessAlive:${pid}`);
+      return true;
+    },
+    resolveUrl: (state) => `http://127.0.0.1:${state.port}`,
+    spawnDaemon: async () => {
+      calls.push('spawnDaemon');
+      return 1;
+    },
+    waitForDaemonResponse: async () => {
+      calls.push('waitForDaemonResponse');
+      return { ok: true, url: 'http://127.0.0.1:5175' };
+    },
+    openExternal: async (url) => {
+      calls.push(`openExternal:${url}`);
+    },
+    writeResponse: (responsePath, payload) => {
+      responses.push({ path: responsePath, payload });
+    },
+    killProcess: () => {
+      calls.push('killProcess');
+    },
+    sleep: async () => {},
+  });
+
+  const exitCode = await handler({
+    action: 'start',
+    responsePath: '/tmp/response.json',
+    openBrowser: true,
+    daemonScriptPath: '/tmp/stats-daemon-runner.js',
+    userDataPath: '/tmp/SubMiner',
+  });
+
+  assert.equal(exitCode, 0);
+  assert.deepEqual(calls, ['isProcessAlive:4242', 'openExternal:http://127.0.0.1:5175']);
+  assert.deepEqual(responses, [
+    {
+      path: '/tmp/response.json',
+      payload: { ok: true, url: 'http://127.0.0.1:5175' },
+    },
+  ]);
+});
+
+test('stats daemon control clears stale state, starts daemon, and waits for response', async () => {
+  const calls: string[] = [];
+  const handler = createRunStatsDaemonControlHandler({
+    statePath: '/tmp/stats-daemon.json',
+    readState: () => ({ pid: 4242, port: 5175, startedAtMs: 1 }),
+    removeState: () => {
+      calls.push('removeState');
+    },
+    isProcessAlive: (pid) => {
+      calls.push(`isProcessAlive:${pid}`);
+      return false;
+    },
+    resolveUrl: (state) => `http://127.0.0.1:${state.port}`,
+    spawnDaemon: async (options) => {
+      calls.push(`spawnDaemon:${options.scriptPath}:${options.responsePath}:${options.userDataPath}`);
+      return 999;
+    },
+    waitForDaemonResponse: async (responsePath) => {
+      calls.push(`waitForDaemonResponse:${responsePath}`);
+      return { ok: true, url: 'http://127.0.0.1:5175' };
+    },
+    openExternal: async (url) => {
+      calls.push(`openExternal:${url}`);
+    },
+    writeResponse: () => {
+      calls.push('writeResponse');
+    },
+    killProcess: () => {
+      calls.push('killProcess');
+    },
+    sleep: async () => {},
+  });
+
+  const exitCode = await handler({
+    action: 'start',
+    responsePath: '/tmp/response.json',
+    openBrowser: false,
+    daemonScriptPath: '/tmp/stats-daemon-runner.js',
+    userDataPath: '/tmp/SubMiner',
+  });
+
+  assert.equal(exitCode, 0);
+  assert.deepEqual(calls, [
+    'isProcessAlive:4242',
+    'removeState',
+    'spawnDaemon:/tmp/stats-daemon-runner.js:/tmp/response.json:/tmp/SubMiner',
+    'waitForDaemonResponse:/tmp/response.json',
+  ]);
+});
+
+test('stats daemon control stops live daemon and treats stale state as success', async () => {
+  const responses: Array<{ path: string; payload: { ok: boolean; url?: string; error?: string } }> =
+    [];
+  const calls: string[] = [];
+  let aliveChecks = 0;
+  const handler = createRunStatsDaemonControlHandler({
+    statePath: '/tmp/stats-daemon.json',
+    readState: () => ({ pid: 4242, port: 5175, startedAtMs: 1 }),
+    removeState: () => {
+      calls.push('removeState');
+    },
+    isProcessAlive: (pid) => {
+      aliveChecks += 1;
+      calls.push(`isProcessAlive:${pid}:${aliveChecks}`);
+      return aliveChecks === 1;
+    },
+    resolveUrl: (state) => `http://127.0.0.1:${state.port}`,
+    spawnDaemon: async () => 1,
+    waitForDaemonResponse: async () => ({ ok: true, url: 'http://127.0.0.1:5175' }),
+    openExternal: async () => {},
+    writeResponse: (responsePath, payload) => {
+      responses.push({ path: responsePath, payload });
+    },
+    killProcess: (pid, signal) => {
+      calls.push(`killProcess:${pid}:${signal}`);
+    },
+    sleep: async () => {},
+  });
+
+  const exitCode = await handler({
+    action: 'stop',
+    responsePath: '/tmp/response.json',
+    openBrowser: false,
+    daemonScriptPath: '/tmp/stats-daemon-runner.js',
+    userDataPath: '/tmp/SubMiner',
+  });
+
+  assert.equal(exitCode, 0);
+  assert.deepEqual(calls, [
+    'isProcessAlive:4242:1',
+    'killProcess:4242:SIGTERM',
+    'isProcessAlive:4242:2',
+    'removeState',
+  ]);
+  assert.deepEqual(responses, [
+    {
+      path: '/tmp/response.json',
+      payload: { ok: true },
+    },
+  ]);
+});