feat: per-app telemetry reset button on app detail page

Adds "Telemetria törlése" button that deletes all telemetry records and
known issues for a specific app. Useful after major app updates when old
data is no longer representative.

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

hub/internal/web/apps.go

@@ -99,12 +99,37 @@ func (s *Server) handleAppDetail(w http.ResponseWriter, r *http.Request, appName
 		"SuggestedLimit": suggestedLimit,
 		"Period":         period,
 		"CSRFToken":      csrfToken,
+		"Flash":          r.URL.Query().Get("flash"),
 	}
 	if err := s.templates.ExecuteTemplate(w, "app_detail.html", data); err != nil {
 		s.logger.Printf("[ERROR] app_detail.html template: %v", err)
 	}
 }
 
+// handleResetAppTelemetry deletes all telemetry and issues for an app, then redirects back.
+func (s *Server) handleResetAppTelemetry(w http.ResponseWriter, r *http.Request, appName string) {
+	telRows, err := s.store.DeleteAppTelemetry(appName)
+	if err != nil {
+		s.logger.Printf("[ERROR] Failed to reset telemetry for %s: %v", appName, err)
+		http.Error(w, "Internal error", http.StatusInternalServerError)
+		return
+	}
+	issueRows, err := s.store.DeleteAppIssues(appName)
+	if err != nil {
+		s.logger.Printf("[ERROR] Failed to reset issues for %s: %v", appName, err)
+		http.Error(w, "Internal error", http.StatusInternalServerError)
+		return
+	}
+	s.logger.Printf("[INFO] Telemetry reset for %s: %d telemetry rows, %d issues deleted", appName, telRows, issueRows)
+
+	period := r.URL.Query().Get("period")
+	target := "/apps/" + appName + "?flash=telemetry_reset"
+	if period != "" {
+		target += "&period=" + period
+	}
+	http.Redirect(w, r, target, http.StatusSeeOther)
+}
+
 // parsePeriod converts a period string to a time.Time cutoff.
 func parsePeriod(s string, defaultDur time.Duration) time.Time {
 	switch s {