refactor(sync): launcher sync command proxies to the app's --sync-cli

The engine now executes only inside the app (libsql): subminer sync
rebuilds the equivalent --sync-cli argv and spawns the discovered app
binary with the terminal attached (stdin for ssh prompts, raw NDJSON
stdout, exit-code passthrough). The bun:sqlite driver binding and the
launcher-side engine shims are gone; flow tests moved to
src/core/services/stats-sync/sync-flow.test.ts, ssh tests to src, and
the merge suite now runs through the libsql driver the app ships.

launcher/sync/bun-driver.ts

@@ -1,23 +0,0 @@
-import { Database } from 'bun:sqlite';
-import type {
-  OpenSyncDb,
-  SyncDb,
-  SyncDbStatement,
-} from '../../src/core/services/stats-sync/driver.js';
-
-// bun:sqlite's Database.query() already caches prepared statements per SQL
-// string, which is exactly what the SyncDb contract asks for.
-export const openBunSyncDb: OpenSyncDb = (dbPath, options): SyncDb => {
-  const db = new Database(dbPath, options);
-  return {
-    query(sql: string): SyncDbStatement {
-      return db.query(sql);
-    },
-    exec(sql: string): void {
-      db.run(sql);
-    },
-    close(): void {
-      db.close();
-    },
-  };
-};

launcher/sync/engine-drivers.test.ts

@@ -1,76 +0,0 @@
-import test from 'node:test';
-import assert from 'node:assert/strict';
-import fs from 'node:fs';
-import os from 'node:os';
-import path from 'node:path';
-import {
-  createImmersionDbFixture,
-  insertFixtureSession,
-} from '../test-support/immersion-db-fixture.js';
-import { openLibsqlSyncDb } from '../../src/core/services/stats-sync/libsql-driver.js';
-import { createDbSnapshot } from '../../src/core/services/stats-sync/shared.js';
-import { mergeSnapshotIntoDb } from '../../src/core/services/stats-sync/merge.js';
-
-const BASE_MS = Date.UTC(2026, 5, 1, 12, 0, 0);
-
-function makeTmpDir(): string {
-  return fs.mkdtempSync(path.join(os.tmpdir(), 'subminer-libsql-sync-test-'));
-}
-
-function countRows(dbPath: string, sql: string): number {
-  const db = openLibsqlSyncDb(dbPath, { readonly: true });
-  try {
-    const row = db.query(sql).get() as { n: number } | undefined;
-    return Number(row?.n ?? 0);
-  } finally {
-    db.close();
-  }
-}
-
-// End-to-end pass of the shared engine over the libsql driver (the binding the
-// Electron app's --sync-cli mode uses): snapshot a fixture DB, merge it into
-// another, and re-merge to confirm idempotence.
-test('libsql driver runs snapshot and merge through the shared engine', () => {
-  const dir = makeTmpDir();
-  try {
-    const localPath = path.join(dir, 'local.sqlite');
-    const remotePath = path.join(dir, 'remote.sqlite');
-    createImmersionDbFixture(localPath);
-    createImmersionDbFixture(remotePath);
-    insertFixtureSession(localPath, {
-      uuid: 'local-1',
-      videoKey: 'showa-e1',
-      animeTitleKey: 'showa',
-      startedAtMs: BASE_MS,
-      applyLifetime: true,
-      words: [{ headword: '見る', word: '見た', reading: 'みた', count: 2 }],
-    });
-    insertFixtureSession(remotePath, {
-      uuid: 'remote-1',
-      videoKey: 'showb-e1',
-      animeTitleKey: 'showb',
-      startedAtMs: BASE_MS + 86_400_000,
-      activeWatchedMs: 900_000,
-      cardsMined: 3,
-      applyLifetime: true,
-      words: [{ headword: '食べる', word: '食べた', reading: 'たべた', count: 1 }],
-    });
-
-    const snapshotPath = path.join(dir, 'remote-snapshot.sqlite');
-    createDbSnapshot(openLibsqlSyncDb, remotePath, snapshotPath);
-    assert.ok(fs.existsSync(snapshotPath));
-    assert.equal(countRows(snapshotPath, 'SELECT COUNT(*) AS n FROM imm_sessions'), 1);
-
-    const summary = mergeSnapshotIntoDb(openLibsqlSyncDb, localPath, snapshotPath);
-    assert.equal(summary.sessionsMerged, 1);
-    assert.equal(summary.videosAdded, 1);
-    assert.equal(countRows(localPath, 'SELECT COUNT(*) AS n FROM imm_sessions'), 2);
-
-    const again = mergeSnapshotIntoDb(openLibsqlSyncDb, localPath, snapshotPath);
-    assert.equal(again.sessionsMerged, 0);
-    assert.equal(again.sessionsAlreadyPresent, 1);
-    assert.equal(countRows(localPath, 'SELECT COUNT(*) AS n FROM imm_sessions'), 2);
-  } finally {
-    fs.rmSync(dir, { recursive: true, force: true });
-  }
-});

launcher/sync/engine-merge.test.ts

@@ -4,7 +4,17 @@ import fs from 'node:fs';
 import os from 'node:os';
 import path from 'node:path';
 import { Database } from 'bun:sqlite';
-import { createDbSnapshot, mergeSnapshotIntoDb } from './sync-db.js';
+import { openLibsqlSyncDb } from '../../src/core/services/stats-sync/libsql-driver.js';
+import { createDbSnapshot as createDbSnapshotWith } from '../../src/core/services/stats-sync/shared.js';
+import { mergeSnapshotIntoDb as mergeSnapshotIntoDbWith } from '../../src/core/services/stats-sync/merge.js';
+
+// The engine only executes inside the app (libsql driver) in production, so
+// these merge tests run through that same binding; bun:sqlite is used only to
+// build fixtures and inspect results.
+const createDbSnapshot = (dbPath: string, outPath: string) =>
+  createDbSnapshotWith(openLibsqlSyncDb, dbPath, outPath);
+const mergeSnapshotIntoDb = (localDbPath: string, snapshotPath: string) =>
+  mergeSnapshotIntoDbWith(openLibsqlSyncDb, localDbPath, snapshotPath);
 import {
   createImmersionDbFixture,
   insertFixtureSession,

launcher/sync/ssh.test.ts

@@ -1,162 +0,0 @@
-import test from 'node:test';
-import assert from 'node:assert/strict';
-import {
-  assertSafeSshHost,
-  detectRemoteShellFlavor,
-  quoteForRemoteShell,
-  resolveRemoteSubminerCommand,
-  runScp,
-  shellQuote,
-  type RemoteRunResult,
-} from './ssh.js';
-
-function remoteResult(status: number, stdout = ''): RemoteRunResult {
-  return { status, stdout, stderr: '' };
-}
-
-test('assertSafeSshHost rejects option-like hosts', () => {
-  assert.throws(() => assertSafeSshHost('-oProxyCommand=touch pwned'), /looks like an option/);
-  assert.throws(() => assertSafeSshHost('-lroot'), /looks like an option/);
-});
-
-test('assertSafeSshHost accepts normal destinations', () => {
-  assert.doesNotThrow(() => assertSafeSshHost('macbook'));
-  assert.doesNotThrow(() => assertSafeSshHost('user@192.168.1.20'));
-  assert.doesNotThrow(() => assertSafeSshHost('ssh-alias'));
-});
-
-test('shellQuote escapes single quotes and wraps in quotes', () => {
-  assert.equal(shellQuote('subminer'), `'subminer'`);
-  assert.equal(shellQuote(`a'; rm -rf ~; '`), `'a'\\''; rm -rf ~; '\\'''`);
-});
-
-test('runScp rejects option-like local endpoints before spawning scp', () => {
-  assert.throws(() => runScp('-oProxyCommand=sh', '/tmp/out.sqlite'), /looks like an option/);
-  assert.throws(() => runScp('/tmp/in.sqlite', '-bad-destination'), /looks like an option/);
-});
-
-test('runScp rejects option-like remote host components', () => {
-  assert.throws(
-    () => runScp('-oProxyCommand=sh:/tmp/in.sqlite', '/tmp/out.sqlite'),
-    /SSH host that looks like an option/,
-  );
-});
-
-test('resolveRemoteSubminerCommand verifies the launcher under the remote runtime PATH', () => {
-  const calls: Array<{ host: string; remoteCommand: string }> = [];
-  const command = resolveRemoteSubminerCommand('macbook', null, 'posix', (host, remoteCommand) => {
-    calls.push({ host, remoteCommand });
-    return remoteResult(0);
-  });
-
-  assert.equal(
-    command,
-    'PATH="$HOME/.local/bin:$HOME/.bun/bin:/opt/homebrew/bin:/usr/local/bin:/usr/bin:/bin:$PATH" subminer',
-  );
-  assert.deepEqual(calls, [
-    {
-      host: 'macbook',
-      remoteCommand:
-        'PATH="$HOME/.local/bin:$HOME/.bun/bin:/opt/homebrew/bin:/usr/local/bin:/usr/bin:/bin:$PATH" subminer --help >/dev/null 2>&1',
-    },
-  ]);
-});
-
-test('resolveRemoteSubminerCommand falls back to the app binary in --sync-cli mode', () => {
-  const probed: string[] = [];
-  const command = resolveRemoteSubminerCommand('media-box', null, 'posix', (_host, remoteCommand) => {
-    probed.push(remoteCommand);
-    return remoteResult(remoteCommand.includes('SubMiner --sync-cli') ? 0 : 1);
-  });
-
-  assert.match(command, / SubMiner --sync-cli$/);
-  // Launcher candidates (PATH + ~/.local/bin) are tried before app binaries.
-  assert.equal(probed.length, 3);
-  assert.match(probed[0]!, / subminer --help /);
-  assert.match(probed[1]!, / ~\/\.local\/bin\/subminer --help /);
-});
-
-test('resolveRemoteSubminerCommand probes a user override as app first, then launcher', () => {
-  const asApp = resolveRemoteSubminerCommand('media-box', '/opt/SubMiner.AppImage', 'posix', (_host, cmd) =>
-    remoteResult(cmd.includes('--sync-cli') ? 0 : 1),
-  );
-  assert.match(asApp, /'\/opt\/SubMiner\.AppImage' --sync-cli$/);
-
-  const asLauncher = resolveRemoteSubminerCommand('media-box', '/opt/subminer', 'posix', (_host, cmd) =>
-    remoteResult(cmd.includes('--sync-cli') ? 1 : 0),
-  );
-  assert.match(asLauncher, /'\/opt\/subminer'$/);
-
-  assert.throws(
-    () => resolveRemoteSubminerCommand('media-box', '/missing', 'posix', () => remoteResult(127)),
-    /Remote command not found on media-box: \/missing/,
-  );
-});
-
-test('resolveRemoteSubminerCommand probes Windows install locations without a PATH prefix', () => {
-  const probed: string[] = [];
-  const command = resolveRemoteSubminerCommand('win-box', null, 'windows-cmd', (_host, cmd) => {
-    probed.push(cmd);
-    return remoteResult(cmd.includes('Programs\\SubMiner\\SubMiner.exe') ? 0 : 1);
-  });
-
-  assert.equal(command, '"%LOCALAPPDATA%\\Programs\\SubMiner\\SubMiner.exe" --sync-cli');
-  assert.equal(probed[0], 'subminer --help');
-  assert.equal(probed[1], '"%LOCALAPPDATA%\\SubMiner\\bin\\subminer.cmd" --help');
-
-  const powershell = resolveRemoteSubminerCommand('win-box', null, 'windows-powershell', (_host, cmd) =>
-    remoteResult(cmd.includes('Programs\\SubMiner\\SubMiner.exe') ? 0 : 1),
-  );
-  assert.equal(powershell, '& "$env:LOCALAPPDATA\\Programs\\SubMiner\\SubMiner.exe" --sync-cli');
-});
-
-test('resolveRemoteSubminerCommand quotes Windows overrides with double quotes', () => {
-  const command = resolveRemoteSubminerCommand(
-    'win-box',
-    'C:/Apps/SubMiner/SubMiner.exe',
-    'windows-cmd',
-    (_host, cmd) => remoteResult(cmd.includes('--sync-cli') ? 0 : 1),
-  );
-  assert.equal(command, '"C:/Apps/SubMiner/SubMiner.exe" --sync-cli');
-});
-
-test('detectRemoteShellFlavor identifies posix, cmd, and powershell remotes', () => {
-  assert.equal(
-    detectRemoteShellFlavor('linux-box', (_host, cmd) =>
-      cmd === 'uname -s' ? remoteResult(0, 'Linux\n') : remoteResult(1),
-    ),
-    'posix',
-  );
-  assert.equal(
-    detectRemoteShellFlavor('win-box', (_host, cmd) => {
-      if (cmd === 'uname -s') return remoteResult(1);
-      if (cmd === 'echo %OS%') return remoteResult(0, 'Windows_NT\r\n');
-      return remoteResult(1);
-    }),
-    'windows-cmd',
-  );
-  assert.equal(
-    detectRemoteShellFlavor('ps-box', (_host, cmd) => {
-      if (cmd === 'uname -s') return remoteResult(1);
-      if (cmd === 'echo %OS%') return remoteResult(0, '%OS%\r\n');
-      if (cmd === 'echo $env:OS') return remoteResult(0, 'Windows_NT\r\n');
-      return remoteResult(1);
-    }),
-    'windows-powershell',
-  );
-  // Unidentifiable remotes keep the pre-detection POSIX behavior.
-  assert.equal(
-    detectRemoteShellFlavor('odd-box', () => remoteResult(1)),
-    'posix',
-  );
-});
-
-test('quoteForRemoteShell quotes per flavor and rejects unsafe Windows values', () => {
-  assert.equal(quoteForRemoteShell('posix', "/tmp/it's"), `'/tmp/it'\\''s'`);
-  assert.equal(
-    quoteForRemoteShell('windows-cmd', 'C:/Users/First Last/AppData/Local/Temp/subminer-sync-ab'),
-    '"C:/Users/First Last/AppData/Local/Temp/subminer-sync-ab"',
-  );
-  assert.throws(() => quoteForRemoteShell('windows-cmd', 'a"b'), /Refusing to quote/);
-  assert.throws(() => quoteForRemoteShell('windows-powershell', 'a\nb'), /Refusing to quote/);
-});

launcher/sync/ssh.ts

@@ -1,13 +0,0 @@
-// Re-exported from the shared stats-sync engine so the launcher and the
-// app's --sync-cli mode resolve remotes and shell out identically.
-export {
-  assertSafeSshHost,
-  detectRemoteShellFlavor,
-  quoteForRemoteShell,
-  resolveRemoteSubminerCommand,
-  runScp,
-  runSsh,
-  shellQuote,
-  type RemoteRunResult,
-  type RemoteShellFlavor,
-} from '../../src/core/services/stats-sync/ssh.js';

launcher/sync/sync-db.ts

@@ -1,12 +0,0 @@
-import { mergeSnapshotIntoDb as mergeSnapshotIntoDbWith } from '../../src/core/services/stats-sync/merge.js';
-import { openBunSyncDb } from './bun-driver.js';
-import type { SyncMergeSummary } from './sync-shared.js';
-
-export type { SyncMergeSummary } from './sync-shared.js';
-export { createDbSnapshot, findLiveStatsDaemonPid } from './sync-shared.js';
-export { formatMergeSummary } from '../../src/core/services/stats-sync/merge.js';
-
-/** bun:sqlite binding of the shared snapshot-merge engine. */
-export function mergeSnapshotIntoDb(localDbPath: string, snapshotPath: string): SyncMergeSummary {
-  return mergeSnapshotIntoDbWith(openBunSyncDb, localDbPath, snapshotPath);
-}

launcher/sync/sync-hosts.ts

@@ -1,41 +0,0 @@
-import fs from 'node:fs';
-import os from 'node:os';
-import { resolveConfigDir } from '../../src/config/path-resolution.js';
-import {
-  getSyncHostsPath,
-  readSyncHostsState,
-  recordSyncResult,
-  writeSyncHostsState,
-  type SyncResultStatus,
-} from '../../src/shared/sync/sync-hosts-store.js';
-
-export function resolveSyncHostsFilePath(): string {
-  const configDir = resolveConfigDir({
-    platform: process.platform,
-    appDataDir: process.env.APPDATA,
-    xdgConfigHome: process.env.XDG_CONFIG_HOME,
-    homeDir: os.homedir(),
-    existsSync: fs.existsSync,
-  });
-  return getSyncHostsPath(configDir);
-}
-
-// Best-effort bookkeeping so hosts synced from the CLI show up in the sync UI;
-// a failure to persist must never fail the sync itself.
-export function recordHostSyncResultToDisk(
-  host: string,
-  status: SyncResultStatus,
-  detail: string | null,
-): void {
-  try {
-    const filePath = resolveSyncHostsFilePath();
-    const state = recordSyncResult(readSyncHostsState(filePath), host, {
-      atMs: Date.now(),
-      status,
-      detail,
-    });
-    writeSyncHostsState(filePath, state);
-  } catch {
-    // best effort
-  }
-}

launcher/sync/sync-shared.ts

@@ -1,31 +0,0 @@
-// bun:sqlite bindings for the shared stats-sync engine. The engine itself
-// lives in src/core/services/stats-sync so the Electron app (libsql) can run
-// the exact same snapshot/merge code via its own driver.
-import {
-  createDbSnapshot as createDbSnapshotWith,
-  createEmptyMergeSummary,
-  findLiveStatsDaemonPid,
-  nowDbTimestamp,
-  readSchemaVersion,
-  assertMergeableSchema,
-  insertRow,
-  tableExists,
-  SCHEMA_VERSION,
-} from '../../src/core/services/stats-sync/shared.js';
-import { openBunSyncDb } from './bun-driver.js';
-
-export {
-  createEmptyMergeSummary,
-  findLiveStatsDaemonPid,
-  nowDbTimestamp,
-  readSchemaVersion,
-  assertMergeableSchema,
-  insertRow,
-  tableExists,
-  SCHEMA_VERSION,
-};
-export type { SyncMergeSummary } from '../../src/core/services/stats-sync/shared.js';
-
-export function createDbSnapshot(dbPath: string, outPath: string): void {
-  createDbSnapshotWith(openBunSyncDb, dbPath, outPath);
-}