feat: restore bench section UI with controls, PID RPM ramp, flowmeter charts, and fix CAN IDs

Restore the full bench control panel from the old source with MVVM architecture:

- Two-column left panel layout: bench info displays (RPM with target/voltage,
  temps, pressures, Q-flow, pump live values) and user commands (direction
  toggle, start/stop with RPM popup and quick-select buttons, oil pump toggle,
  turn downcounter with CAN send)
- PID RPM ramp controller (BenchPidController) with bumpless startup,
  anti-windup, and derivative-on-measurement for smooth motor speed transitions
- Real-time flowmeter charts (LiveChartsCore) for Q-Delivery and Q-Over
  with tolerance band overlays
- Bench/pump CAN liveness detection in PcanAdapter (receive-only IDs)
- K-Line connection status indicator (placeholder)
- Periodic relay bitmask sender (~21ms) and ElectronicMsg keepalive start
  on CAN connect, pump sender starts immediately on pump load

Fix critical CAN message ID bug: default bench XML values were incorrectly
converted from old source (decimal-notation hex parsed as actual hex digits,
e.g. "10" -> "A" instead of keeping "10" which parses as 0x10). Corrected
all IDs to match hardware: 0x10, 0x11, 0x13, 0x14, 0x15, 0x50, 0x51, 0x55.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Services/IBenchService.cs

@@ -113,9 +113,33 @@ namespace HC_APTBS.Services
         /// <summary>
         /// Commands the bench motor to the specified RPM by computing and applying
         /// the corresponding voltage from the RPM-to-voltage lookup table.
+        /// Used by automated test execution for direct voltage jumps.
         /// </summary>
         void SetRpm(double rpm);
 
+        /// <summary>
+        /// Starts the PID-based RPM ramp controller to smoothly reach the target RPM.
+        /// Sends an initial voltage jump from the RPM-voltage lookup table, then hands
+        /// control to the PID loop after an approach delay.
+        /// Used for interactive (manual) bench control.
+        /// </summary>
+        /// <param name="targetRpm">Desired RPM setpoint.</param>
+        void StartRpmPid(double targetRpm);
+
+        /// <summary>
+        /// Stops the PID RPM controller, sends 0 V to the motor.
+        /// </summary>
+        void StopRpmPid();
+
+        /// <summary>The last RPM target that was commanded via <see cref="SetRpm"/> or <see cref="StartRpmPid"/>.</summary>
+        double LastTargetRpm { get; }
+
+        /// <summary>The last voltage value sent to the motor CAN parameter.</summary>
+        double LastCommandVoltage { get; }
+
+        /// <summary>Raised after a voltage command is sent to the motor (from <see cref="SetRpm"/> or the PID loop).</summary>
+        event Action? RpmCommandSent;
+
         // ── Temperature control ───────────────────────────────────────────────────
 
         /// <summary>
@@ -136,6 +160,18 @@ namespace HC_APTBS.Services
         /// <param name="state">True = ON, false = OFF.</param>
         void SetRelay(string relayName, bool state);
 
+        /// <summary>
+        /// Transmits the current relay bitmask once. Called on CAN connect so the
+        /// bench controller receives the initial relay state immediately.
+        /// </summary>
+        void SendInitialRelayState();
+
+        /// <summary>Starts the periodic relay bitmask sender (~21 ms cycle).</summary>
+        void StartRelaySender();
+
+        /// <summary>Stops the periodic relay bitmask sender.</summary>
+        void StopRelaySender();
+
         // ── Test execution ────────────────────────────────────────────────────────
 
         /// <summary>