feat(api): persist and expose garmin_connected on successful auth

backend/internal/api/auth.go

@@ -1,7 +1,9 @@
 package api
 
 import (
+	"context"
 	"encoding/json"
+	"log"
 	"net/http"
 
 	"geniusrun/backend/internal/garmin"
@@ -25,11 +27,22 @@ func authStatusString(s garmin.AuthStatus) string {
 	}
 }
 
-func (s *Server) recordAuthResult(userID int64, res garmin.AuthResult) {
+// recordAuthResult updates the in-memory auth status/message for userID,
+// and -- on a successful authentication -- persists that this account has
+// connected to Garmin at least once (store.MarkGarminConnected), which is
+// what the login gate actually checks (the in-memory auth status resets on
+// every backend restart; this doesn't).
+func (s *Server) recordAuthResult(ctx context.Context, userID int64, res garmin.AuthResult) {
 	s.mu.Lock()
 	s.userAuthStatus[userID] = res.Status
 	s.userAuthMessage[userID] = res.Message
 	s.mu.Unlock()
+
+	if res.Status == garmin.AuthSuccess {
+		if err := s.DB.MarkGarminConnected(ctx, userID); err != nil {
+			log.Printf("api: mark garmin connected for user %d: %v", userID, err)
+		}
+	}
 }
 
 func (s *Server) handleAuthLogin(w http.ResponseWriter, r *http.Request) {
@@ -44,7 +57,7 @@ func (s *Server) handleAuthLogin(w http.ResponseWriter, r *http.Request) {
 		writeError(w, http.StatusBadGateway, err.Error())
 		return
 	}
-	s.recordAuthResult(userID, res)
+	s.recordAuthResult(r.Context(), userID, res)
 	writeJSON(w, http.StatusOK, authResponse{Status: authStatusString(res.Status), Message: res.Message})
 }
 
@@ -72,7 +85,7 @@ func (s *Server) handleAuthMFA(w http.ResponseWriter, r *http.Request) {
 		writeError(w, http.StatusBadGateway, err.Error())
 		return
 	}
-	s.recordAuthResult(userID, res)
+	s.recordAuthResult(r.Context(), userID, res)
 	writeJSON(w, http.StatusOK, authResponse{Status: authStatusString(res.Status), Message: res.Message})
 }