[wifi] Track roam target BSSID to detect successful roam via retry

When a roam connection fails on the first attempt, retry_connect()
transitions to RECONNECTING. The subsequent scan-based retry may
connect to the same better AP, but the success handler treated all
RECONNECTING connections as failed roams and preserved the attempts
counter. This meant a successful roam (that needed two tries) would
incorrectly consume an attempt.

Fix by storing the roam target BSSID and checking it on reconnection.
If the device connected to the intended target, reset the counter
(successful roam). If it fell back to a different AP, preserve the
counter (failed roam, prevent ping-pong).

esphome/components/wifi/wifi_component.cpp

@@ -287,19 +287,25 @@ bool CompactString::operator==(const StringRef &other) const {
 /// │    │  (counter reset to 0)            │    │  (retry_connect called) │
 /// │    └──────────────────────────────────┘    └───────────┬─────────────┘
 /// │                                                        │             │
-/// │                                                        ↓             │
-/// │                                            ┌───────────────────────┐ │
-/// │                                            │  → IDLE               │ │
-/// │                                            │  (counter preserved!) │ │
-/// │                                            └───────────────────────┘ │
+/// │                                              ┌─────────┴─────────┐   │
+/// │                                              ↓                   ↓   │
+/// │                                      on target BSSID    on other AP  │
+/// │                                              │                   │   │
+/// │                                              ↓                   ↓   │
+/// │                                   ┌──────────────────┐ ┌────────────┐│
+/// │                                   │  → IDLE          │ │  → IDLE    ││
+/// │                                   │  (counter reset) │ │  (counter  ││
+/// │                                   │  (roam worked!)  │ │  preserved)││
+/// │                                   └──────────────────┘ └────────────┘│
 /// │                                                                      │
 /// │  Key behaviors:                                                      │
 /// │  - After 3 checks: attempts >= 3, stop checking                      │
 /// │  - Non-roaming disconnect: clear_roaming_state_() resets counter     │
-/// │  - Disconnect during scan (SCANNING→RECONNECTING): counter preserved  │
+/// │  - Disconnect during scan (SCANNING→RECONNECTING): counter preserved │
 /// │  - Disconnect after scan (within grace period): counter preserved    │
 /// │  - Roaming success (CONNECTING→IDLE): counter reset (can roam again) │
-/// │  - Roaming fail (RECONNECTING→IDLE): counter preserved (ping-pong)   │
+/// │  - Roaming success via retry (on target BSSID): counter reset        │
+/// │  - Roaming fail (RECONNECTING on other AP): counter preserved        │
 /// └──────────────────────────────────────────────────────────────────────┘
 
 // Use if-chain instead of switch to avoid jump table in RODATA (wastes RAM on ESP8266)
@@ -1577,17 +1583,26 @@ void WiFiComponent::check_connecting_finished(uint32_t now) {
     // Only preserve attempts if reconnecting after a failed roam attempt
     // This prevents ping-pong between APs when a roam target is unreachable
     if (this->roaming_state_ == RoamingState::CONNECTING) {
-      // Successful roam to better AP - reset attempts so we can roam again later
+      // Successful roam to better AP on first try - reset attempts so we can roam again later
       ESP_LOGD(TAG, "Roam successful");
       this->roaming_attempts_ = 0;
     } else if (this->roaming_state_ == RoamingState::RECONNECTING) {
-      // Failed roam, reconnected via normal recovery - keep attempts to prevent ping-pong
-      ESP_LOGD(TAG, "Reconnected after failed roam (attempt %u/%u)", this->roaming_attempts_, ROAMING_MAX_ATTEMPTS);
+      // Check if we ended up on the roam target despite needing a retry
+      // (e.g., first connect failed but scan-based retry found and connected to the same better AP)
+      bssid_t current_bssid = this->wifi_bssid();
+      if (this->roaming_target_bssid_ != bssid_t{} && current_bssid == this->roaming_target_bssid_) {
+        ESP_LOGD(TAG, "Roam successful (via retry)");
+        this->roaming_attempts_ = 0;
+      } else {
+        // Failed roam, reconnected to different AP - keep attempts to prevent ping-pong
+        ESP_LOGD(TAG, "Reconnected after failed roam (attempt %u/%u)", this->roaming_attempts_, ROAMING_MAX_ATTEMPTS);
+      }
     } else {
       // Normal connection (boot, credentials changed, etc.)
       this->roaming_attempts_ = 0;
     }
     this->roaming_state_ = RoamingState::IDLE;
+    this->roaming_target_bssid_ = {};
 
     // Clear all priority penalties - the next reconnect will happen when an AP disconnects,
     // which means the landscape has likely changed and previous tracked failures are stale
@@ -2317,6 +2332,7 @@ void WiFiComponent::clear_roaming_state_() {
   this->roaming_attempts_ = 0;
   this->roaming_last_check_ = 0;
   this->roaming_scan_end_ = 0;
+  this->roaming_target_bssid_ = {};
   this->roaming_state_ = RoamingState::IDLE;
 }
 
@@ -2453,6 +2469,7 @@ void WiFiComponent::process_roaming_scan_() {
 
   // Mark as roaming attempt - affects retry behavior if connection fails
   this->roaming_state_ = RoamingState::CONNECTING;
+  this->roaming_target_bssid_ = best->get_bssid();
 
   // Connect directly - wifi_sta_connect_ handles disconnect internally
   this->start_connecting(roam_params);

esphome/components/wifi/wifi_component.h

@@ -790,7 +790,8 @@ class WiFiComponent final : public Component {
   uint32_t last_connected_{0};
   uint32_t reboot_timeout_{};
   uint32_t roaming_last_check_{0};
-  uint32_t roaming_scan_end_{0};  // Timestamp when last roaming scan completed
+  uint32_t roaming_scan_end_{0};    // Timestamp when last roaming scan completed
+  bssid_t roaming_target_bssid_{};  // BSSID of the AP we're trying to roam to
 #ifdef USE_WIFI_AP
   uint32_t ap_timeout_{};
 #endif