Add Auto publishing mode to UDPStreamer; optimise WebUI hub

UDPStreamer:
- Add PublishingMode = "Strict" | "Auto" config parameter
- Add MinRefreshRate (Hz) for Auto mode; uses HRT phase-locked tick
  counting to rate-limit sends without accumulation buffers
- Fix high-frequency integration test configs to use newline-separated
  key-value pairs (MARTe2 StandardParser does not treat ';' as delimiter)
- Add 3 new unit tests (AutoMode_Valid, AutoMode_MissingRefreshRate,
  UnknownPublishingMode); all 33 tests passing

WebUI hub:
- Skip ring-buffer LTTB writes when zoom has not been accessed in 10 s,
  reducing idle CPU usage
- Use unsafe float64→bytes reinterpretation to eliminate per-element
  encoding overhead in the hot broadcast path

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

Source/Components/DataSources/UDPStreamer/UDPStreamer.h

@@ -46,6 +46,18 @@
 
 namespace MARTe {
 
+/**
+ * @brief Publishing mode for the background sender thread.
+ *
+ * - Strict: send one UDP packet on every Synchronise() call (legacy behaviour).
+ * - Auto:   buffer successive ticks and only flush when the HRT-based flush
+ *           interval has elapsed. Controlled by MinRefreshRate (Hz).
+ */
+typedef enum {
+    UDPStreamerPublishStrict = 0u, /**< Send on every RT cycle (default) */
+    UDPStreamerPublishAuto   = 1u  /**< Rate-limited: flush at MinRefreshRate Hz */
+} UDPStreamerPublishMode;
+
 /**
  * @brief Quantization types for float signals.
  */
@@ -153,6 +165,8 @@ static const uint8 UDPS_TYPECODE_UNKNOWN = 255u;
  *     MaxPayloadSize = 1400     // Optional (default 1400); max payload bytes per UDP datagram
  *     CPUMask = 0x2             // Optional, affinity for background thread
  *     StackSize = 1048576       // Optional, stack size for background thread
+ *     PublishingMode = "Auto"   // Optional: "Strict" (default) | "Auto"
+ *     MinRefreshRate = 120      // Optional (Hz); only used when PublishingMode = "Auto"
  *     Signals = {
  *         Time = {
  *             Type = uint64
@@ -292,10 +306,13 @@ private:
     static uint8 TypeDescriptorToCode(TypeDescriptor td);
 
     /* Configuration parameters */
-    uint16 port;            /**< UDP server port */
-    uint32 maxPayloadSize;  /**< Max payload bytes per UDP packet (excluding header) */
-    uint32 cpuMask;         /**< Background thread CPU affinity */
-    uint32 stackSize;       /**< Background thread stack size */
+    uint16 port;                        /**< UDP server port */
+    uint32 maxPayloadSize;              /**< Max payload bytes per UDP packet (excluding header) */
+    uint32 cpuMask;                     /**< Background thread CPU affinity */
+    uint32 stackSize;                   /**< Background thread stack size */
+    UDPStreamerPublishMode publishMode;  /**< Strict or Auto publishing mode */
+    float64 minRefreshRate;             /**< Minimum flush rate (Hz) for Auto mode */
+    uint64 flushPeriodTicks;            /**< HRT ticks per flush interval (computed from minRefreshRate) */
 
     /* Signal metadata */
     uint32                 numSigs;       /**< Number of signals */