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>

Infrastructure/Pcan/PcanAdapter.cs

@@ -48,11 +48,27 @@ namespace HC_APTBS.Infrastructure.Pcan
         private AutoResetEvent? _receiveEvent;
         private volatile bool _stopRead = true;
 
+        // ── Liveness tracking ────────────────────────────────────────────────────
+
+        private const int LivenessTimeoutMs = 500;
+        private HashSet<uint> _benchMessageIds = new();
+        private HashSet<uint> _pumpMessageIds = new();
+        private DateTime _lastBenchFrameUtc = DateTime.MinValue;
+        private DateTime _lastPumpFrameUtc = DateTime.MinValue;
+        private bool _benchAlive;
+        private bool _pumpAlive;
+
         // ── ICanService ──────────────────────────────────────────────────────────
 
         /// <inheritdoc/>
         public event Action<string, bool>? StatusChanged;
 
+        /// <inheritdoc/>
+        public event Action<bool>? BenchLivenessChanged;
+
+        /// <inheritdoc/>
+        public event Action<bool>? PumpLivenessChanged;
+
         /// <inheritdoc/>
         public TPCANStatus CurrentStatus { get; private set; } = TPCANStatus.PCAN_ERROR_OK;
 
@@ -186,6 +202,18 @@ namespace HC_APTBS.Infrastructure.Pcan
             }
         }
 
+        /// <inheritdoc/>
+        public void RegisterBenchMessageIds(IReadOnlyCollection<uint> ids)
+        {
+            _benchMessageIds = new HashSet<uint>(ids);
+        }
+
+        /// <inheritdoc/>
+        public void RegisterPumpMessageIds(IReadOnlyCollection<uint> ids)
+        {
+            _pumpMessageIds = new HashSet<uint>(ids);
+        }
+
         // ── ICanService: transmit ─────────────────────────────────────────────────
 
         /// <inheritdoc/>
@@ -289,6 +317,9 @@ namespace HC_APTBS.Infrastructure.Pcan
                     EmitStatusChanged(status);
                 }
 
+                // Check liveness timeouts.
+                CheckLivenessTimeout();
+
                 // Configurable polling interval to avoid pegging the CPU.
                 // Typical value: 2–50 ms depending on operational phase.
                 Thread.Sleep(2);
@@ -336,6 +367,27 @@ namespace HC_APTBS.Infrastructure.Pcan
 
             if (!snapshot.TryGetValue(frame.ID, out var parameters)) return;
 
+            // Track liveness for bench and pump frame groups.
+            var now = DateTime.UtcNow;
+            if (_benchMessageIds.Contains(frame.ID))
+            {
+                _lastBenchFrameUtc = now;
+                if (!_benchAlive)
+                {
+                    _benchAlive = true;
+                    BenchLivenessChanged?.Invoke(true);
+                }
+            }
+            if (_pumpMessageIds.Contains(frame.ID))
+            {
+                _lastPumpFrameUtc = now;
+                if (!_pumpAlive)
+                {
+                    _pumpAlive = true;
+                    PumpLivenessChanged?.Invoke(true);
+                }
+            }
+
             byte[] data = frame.DATA;
 
             foreach (var param in parameters)
@@ -472,6 +524,27 @@ namespace HC_APTBS.Infrastructure.Pcan
             return raw;
         }
 
+        /// <summary>
+        /// Checks if bench or pump frame reception has timed out and fires
+        /// liveness events on transition from alive to dead.
+        /// </summary>
+        private void CheckLivenessTimeout()
+        {
+            var now = DateTime.UtcNow;
+
+            if (_benchAlive && (now - _lastBenchFrameUtc).TotalMilliseconds > LivenessTimeoutMs)
+            {
+                _benchAlive = false;
+                BenchLivenessChanged?.Invoke(false);
+            }
+
+            if (_pumpAlive && (now - _lastPumpFrameUtc).TotalMilliseconds > LivenessTimeoutMs)
+            {
+                _pumpAlive = false;
+                PumpLivenessChanged?.Invoke(false);
+            }
+        }
+
         // ── IIR low-pass filter ───────────────────────────────────────────────────
 
         /// <summary>