sprint-4: Project Editor + .appack compiler + IRudderActuator HAL + dual sensor config

Cherry-pick of ab28cb7 onto main (was missing from main branch history).

Python:
- arautopilot/core/sensor_config.py: RudderSensorConfig + DualRudderSensorConfig
  (AS5048A SPI / potentiometer, dual with cross-validation thresholds)
- arautopilot/core/vessel_config.py: add sensors: DualRudderSensorConfig field
- arautopilot/studio/compiler/appack.py: .appack compiler (ZIP with
  manifest.json + project.yaml + firmware_config.h + install_notes.txt)
- arautopilot/studio/editors/project_editor.py: full project config editor
  (vessel / actuator / sensors / PID, RBAC-gated fields, save/load .yaml/.json)
- arautopilot/studio/main_window.py: wire ProjectEditorWidget into Project tab
- tests: test_sensor_config.py (11 tests) + test_appack_compiler.py (10 tests)

Firmware:
- hal/rudder_actuator_iface.h: IRudderActuator abstract interface
- hal/rudder_actuator_hydraulic.h: reversible hydraulic pump (LEDC PWM)
- hal/rudder_actuator_electric.h: reversible DC motor + deadband compensation
- hal/rudder_actuator_factory.h: build-time type selection via AR_ACTUATOR_TYPE

Tests: 483 passed (was 462, +21 Sprint 4)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

arautopilot/studio/main_window.py

@@ -24,6 +24,7 @@ from PySide6.QtWidgets import (
 )
 
 from arautopilot.core.rbac import capabilities_of
+from arautopilot.studio.editors.project_editor import ProjectEditorWidget
 from arautopilot.studio.flash_console import FlashConsoleWidget
 from arautopilot.studio.session import Session
 from arautopilot.version import __version__
@@ -74,11 +75,7 @@ class StudioMainWindow(QMainWindow):
 
         tabs.addTab(self._build_overview_tab(), "Overview")
         tabs.addTab(FlashConsoleWidget(self._session), "Flash Console")
-        tabs.addTab(self._placeholder_tab(
-            "Project configurator -- Sprint 4.\n\n"
-            "Will let you create / edit a per-vessel ProjectConfig and "
-            "compile it into an .appack for deployment."
-        ), "Project")
+        tabs.addTab(ProjectEditorWidget(self._session), "Project")
         tabs.addTab(self._placeholder_tab(
             "Telemetry -- Sprint 4.\n\n"
             "Live Modbus telemetry from the connected AR-NMEA-IO board."