Integrate SQLite export functionality

pipeline/includes/services/date_time_provider.h

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+#ifndef BIERGARTEN_PIPELINE_INCLUDES_SERVICES_DATE_TIME_PROVIDER_H_
+#define BIERGARTEN_PIPELINE_INCLUDES_SERVICES_DATE_TIME_PROVIDER_H_
+
+/**
+ * @file services/date_time_provider.h
+ * @brief Abstraction for UTC timestamp generation.
+ */
+
+#include <chrono>
+#include <ctime>
+#include <iomanip>
+#include <sstream>
+#include <stdexcept>
+#include <string>
+
+/**
+ * @brief Interface for UTC timestamp providers.
+ */
+class IDateTimeProvider {
+   public:
+
+   /// @brief Virtual destructor for polymorphic cleanup.
+   virtual ~IDateTimeProvider() = default;
+
+
+   IDateTimeProvider() = default;
+  IDateTimeProvider(const IDateTimeProvider&) = delete;
+  IDateTimeProvider& operator=(const IDateTimeProvider&) = delete;
+  IDateTimeProvider(IDateTimeProvider&&) = delete;
+  IDateTimeProvider& operator=(IDateTimeProvider&&) = delete;
+
+  /**
+   * @brief Returns the current UTC timestamp in a file-safe format.
+   *
+   * @return UTC timestamp string.
+   */
+  virtual std::string GetUtcTimestamp() = 0;
+};
+
+/**
+ * @brief Timestamp provider backed by the system clock.
+ */
+class SystemDateTimeProvider final : public IDateTimeProvider {
+ public:
+  std::string GetUtcTimestamp() override {
+    constexpr int kFractionalSecondWidth = 6;
+
+    const auto now = std::chrono::system_clock::now();
+    const auto now_time = std::chrono::system_clock::to_time_t(now);
+    const std::tm* utc_time_ptr = std::gmtime(&now_time);
+    if (utc_time_ptr == nullptr) {
+      throw std::runtime_error("Failed to format UTC timestamp");
+    }
+
+    const auto fractional_seconds =
+        std::chrono::duration_cast<std::chrono::microseconds>(
+            now.time_since_epoch()) %
+        std::chrono::seconds(1);
+
+    std::ostringstream output;
+    output << std::put_time(utc_time_ptr, "%Y-%m-%dT%H-%M-%S");
+    output << '.' << std::setw(kFractionalSecondWidth) << std::setfill('0')
+           << fractional_seconds.count() << 'Z';
+    return output.str();
+  }
+};
+
+#endif  // BIERGARTEN_PIPELINE_INCLUDES_SERVICES_DATE_TIME_PROVIDER_H_