Assign sequential pod IDs from the master with NVS-stable bindings.

Replaces MAC-byte self-IDs with master allocation (1–255), slave preferred-ID reconnect, debug reset via UART/UI, and rate-limited ASSIGN to avoid ESP-NOW NO_MEM storms.

Co-authored-by: Cursor <cursoragent@cursor.com>

main/client_registry.h

@@ -47,6 +47,8 @@ typedef struct {
   uint32_t lipo1_mv;
   uint32_t lipo2_mv;
   uint32_t battery_updated_at;
+  /** Master: last ESPNOW_ASSIGN_ID send time (rate-limit resends). */
+  uint32_t last_assign_sent_at;
 } client_info_t;
 
 #define CLIENT_REGISTRY_DEFAULT_ACCEL_DEADZONE 100u
@@ -55,6 +57,23 @@ typedef struct {
 
 void client_registry_init(void);
 
+/**
+ * Assign a stable logical id for mac (1…255). Honors preferred if free or
+ * already owned by mac; otherwise allocates the next free id. Persists the
+ * master id map to NVS.
+ */
+esp_err_t client_registry_assign_id(const uint8_t mac[CLIENT_MAC_LEN],
+                                    uint32_t preferred_id, uint32_t *out_id);
+
+/**
+ * Clear NVS id map, RAM map, and all live registry slots. Does not notify
+ * slaves (caller sends CLEAR_ID_BINDING).
+ */
+void client_registry_clear_id_map(void);
+
+/** Record that ASSIGN_ID was sent to this MAC (for resend rate limiting). */
+void client_registry_mark_assign_sent(const uint8_t mac[CLIENT_MAC_LEN]);
+
 /** Milliseconds since boot (same clock as stored ping timestamps). */
 uint32_t client_registry_now_ms(void);
 
@@ -75,7 +94,10 @@ esp_err_t client_registry_heartbeat(const uint8_t mac[CLIENT_MAC_LEN],
                                     uint32_t id, uint32_t version, bool used,
                                     bool *out_is_new, bool *out_reactivated);
 
-/** Mark clients inactive when last_success_ping_at is older than timeout_ms. */
+/**
+ * Drop live registry slots whose last_success_ping_at is older than
+ * timeout_ms (NVS id map unchanged). Offline clients disappear from CLIENT_INFO.
+ */
 void client_registry_check_timeouts(uint32_t timeout_ms);
 
 size_t client_registry_count(void);