test: rebuildable bundles, npm test entry point

- esbuild alias fixed in the session/sysinfo/sftp test commands (they
  could not build at all), .sftp-svc.mjs build documented, real
  connection-stability assertions
- tests/build-bundles.cjs builds every bundle fresh; npm test runs the
  seven offline suites; esbuild pinned in devDependencies
- remove the assertion-less .exact-inline.mjs; ignore/clean test temp dirs

tests/build-bundles.cjs

@@ -0,0 +1,43 @@
+/* Rebuild every esbuild bundle the tests load, so a test run can never exercise
+   a stale bundle. `npm test` calls this first; run it standalone when you only
+   want fresh bundles.
+
+   The aliases live here (and nowhere else) so every bundle resolves `electron`
+   and `@shared` the same way. A bundle built without
+   `--alias:@shared=./src/shared` does not even compile: pty.ts reaches
+   @shared/theme through settingsStore.ts -> windowChrome.ts.
+
+   Usage: node tests/build-bundles.cjs */
+const path = require('node:path')
+const esbuild = require('esbuild')
+
+const ROOT = path.join(__dirname, '..')
+
+const BUNDLES = [
+  // Real session layer: pty.ts also re-exports the ssh + sysinfo engines.
+  { entry: 'src/main/pty.ts', out: 'tests/.session-e2e.cjs', external: ['@lydell/node-pty', 'ssh2'] },
+  // ESM (`.mjs`): tests/sftp-*.mjs load it with `await import()`.
+  { entry: 'src/main/sftp.ts', out: 'tests/.sftp-svc.mjs', format: 'esm', external: ['ssh2'] },
+  { entry: 'src/main/commands.ts', out: 'tests/.commands-store.cjs' },
+  { entry: 'src/main/settingsStore.ts', out: 'tests/.settings-store.cjs' },
+  // zmodem.js stays bundled (NOT external) — the test drives a second in-process
+  // Sentry from the same library.
+  { entry: 'src/main/zmodem.ts', out: 'tests/.zmodem-e2e.cjs', external: ['ssh2'] },
+  // The smoke test imports the renderer engine (.ts), so it needs bundling too.
+  { entry: 'tests/hl-split-smoke.mjs', out: 'tests/.hl-split-smoke.cjs' }
+]
+
+for (const { entry, out, format = 'cjs', external = [] } of BUNDLES) {
+  esbuild.buildSync({
+    absWorkingDir: ROOT,
+    entryPoints: [path.join(ROOT, entry)],
+    outfile: path.join(ROOT, out),
+    bundle: true,
+    platform: 'node',
+    format,
+    external,
+    alias: { electron: './tests/electron-stub.cjs', '@shared': './src/shared' },
+    logLevel: 'warning'
+  })
+  console.log(`built ${out}`)
+}