Add Ascon capability advertisement and tracking fields

Author: liquidraver

src/helpers/AdvertDataHelpers.h

@@ -16,6 +16,9 @@
 #define ADV_FEAT2_MASK        0x40   // FUTURE
 #define ADV_NAME_MASK         0x80
 
+// FEAT1 bit flags (encoded when ADV_FEAT1_MASK is set)
+#define ADV_FEAT1_ASCON_CAPABLE 0x0001
+
 class AdvertDataBuilder {
   uint8_t _type;
   bool _has_loc;

src/helpers/ClientACL.h

@@ -18,6 +18,7 @@ struct ClientInfo {
   uint8_t shared_secret[PUB_KEY_SIZE];
   uint32_t last_timestamp;   // by THEIR clock  (transient)
   uint32_t last_activity;    // by OUR clock    (transient)
+  bool supports_ascon;       // Peer advertised Ascon encryption capability in FEAT1 (transient)
   union  {
     struct {
       uint32_t sync_since;  // sync messages SINCE this timestamp (by OUR clock)

src/helpers/ContactInfo.h

@@ -10,6 +10,7 @@ struct ContactInfo {
   uint8_t flags;
   int8_t out_path_len;
   mutable bool shared_secret_valid; // flag to indicate if shared_secret has been calculated
+  bool supports_ascon;  // Peer advertised Ascon encryption capability in FEAT1
   uint8_t out_path[MAX_PATH_SIZE];
   uint32_t last_advert_timestamp;   // by THEIR clock
   uint32_t lastmod;  // by OUR clock