feat: add user configurable device serial for adb based emulators

[martinmiglio]

Summary

Fixes ADB multi-device conflicts that caused false positives for offline emulator detection and app installation checks. Users with multiple ADB devices (USB phones, other emulators, etc.) can now specify which device to target.

Key changes:

• Added user-configurable device serial dropdowns for Google Play and BlueStacks emulators
• Refactored ADB command execution to automatically scope commands with -s device_serial
• Consolidated duplicate adb() implementations into a single base class method
• Added input validation to prevent command injection via device serial

Problem

When multiple ADB devices are connected, commands like adb shell pm list packages fail with:

adb.exe: more than one device/emulator

This caused:

• False "Emulator is offline" errors when other devices were offline
• "com.supercell.clashroyale not installed" errors even when the app was installed
• General unreliability for users with Android phones or multiple emulators connected

Solution

All ADB commands are now scoped to a specific device using the -s flag. Users can:

1. Leave the device field empty for auto-detection (existing behavior)
2. Select a specific device from a dropdown that refreshes on open
3. Manually enter a device address (e.g., localhost:6520, 127.0.0.1:5567)

Architecture

                    ┌──────────────────────────────┐
                    │    BaseEmulatorController    │
                    │          (ABC)               │
                    │──────────────────────────────│
                    │ + click()                    │
                    │ + swipe()                    │
                    │ + screenshot()               │
                    │ + start_app()                │
                    │ + stop()                     │
                    │ + create()                   │
                    └──────────────┬───────────────┘
                                   │
                                   │ inherits
                                   ▼
                    ┌──────────────────────────────┐
                    │     AdbBasedController       │
                    │          (ABC)               │
                    │──────────────────────────────│
                    │ device_serial: str | None    │
                    │ adb_path: str = "adb"        │
                    │ adb_server_port: int | None  │
                    │ adb_env: dict | None         │
                    │──────────────────────────────│
                    │ + adb(command) ◄─────────────┼── Shared implementation
                    │ + _check_app_installed()     │   Auto-adds -s flag
                    │ + list_devices()             │
                    │ + list_online_devices()      │
                    │ + click() / swipe() / ...    │
                    └──────────────┬───────────────┘
                                   │
           ┌───────────────────────┼───────────────────────┐
           │                       │                       │
           ▼                       ▼                       ▼
┌──────────────────┐   ┌──────────────────┐   ┌──────────────────┐
│  AdbController   │   │ GooglePlayEmu... │   │ BlueStacksEmu... │
│──────────────────│   │──────────────────│   │──────────────────│
│ Uses system adb  │   │ Uses bundled adb │   │ Uses bundled adb │
│ No custom port   │   │ Default: 6520    │   │ Private server   │
│──────────────────│   │──────────────────│   │ Port: 5041       │
│ device_serial:   │   │ device_serial:   │   │──────────────────│
│   user-provided  │   │   user-provided  │   │ device_serial:   │
│   or discovered  │   │   or default     │   │   user-provided  │
└──────────────────┘   └──────────────────┘   │   or auto-detect │
                                              └──────────────────┘

Command flow:
─────────────
self.adb("shell pm list packages")
         │
         ▼
AdbBasedController.adb() builds:
  "{adb_path}" [-P {port}] [-s {serial}] {command}
         │
         ▼
Subprocess executes:
  "C:\...\adb.exe" -s localhost:6520 shell pm list packages

Test plan

• Test Google Play emulator with default device (localhost:6520)
• Test Google Play emulator with custom device serial
• Test BlueStacks with auto-detected device (leave field empty)
• Test BlueStacks with user-specified device serial
• Test ADB controller with multiple devices connected
• Verify device dropdown refreshes when opened
• Verify invalid device serial shows error before starting
• Test with USB-connected Android phone alongside emulator

[JJamesWWang]

changes generally lgtm, with some minor comments.
tested with google play and changes work as intended 👍🏼

[JJamesWWang]

nit: there's room for this to be refactored into something like check_device_exists(emulator_type, key_serial, emulator_controller)

[JJamesWWang]

nit: it may be more correct to regex -s <...>; right now your check is:

        if not self._is_server_command(command) and self.device_serial:
            parts.append(f"-s {self.device_serial}")

and running self._is_server_command(full_command) will still return false because you append -s at the end of the command, while here you're checking that the command starts with -s