Fix double/float precision in timeSamples printing

Print double and float values with full precision in timeSamples to avoid
truncation of significant digits.

Changes:
- Add specializations for print_type<double> and print_type<float>
- Use std::setprecision(std::numeric_limits<T>::max_digits10) for full precision
- Add includes for <iomanip> and <limits>

Before:
- double: 3.14159 (truncated to ~6 digits)
- float: similar truncation

After:
- double: 3.1415926535897931 (17 digits - max_digits10 for double)
- float: 3.14159012 (9 digits - max_digits10 for float)

This ensures no precision loss when round-tripping USD files with
double/float timeSamples values.

Test: timesamples-scalar-double-001.usda now prints with full precision

src/timesamples-pprint.cc

@@ -6,6 +6,8 @@
 #include <sstream>
 #include <cstring>
 #include <map>
+#include <iomanip>
+#include <limits>
 
 #ifdef TINYUSDZ_ENABLE_THREAD
 #include <thread>
@@ -194,6 +196,28 @@ void print_type<char>(OutputAdapter& out, const uint8_t* data) {
   out.write(static_cast<int>(value));
 }
 
+// Specialization for double - print with full precision
+template<>
+void print_type<double>(OutputAdapter& out, const uint8_t* data) {
+  double value;
+  std::memcpy(&value, data, sizeof(double));
+  std::stringstream ss;
+  ss << std::setprecision(std::numeric_limits<double>::max_digits10);
+  ss << value;
+  out.write(ss.str());
+}
+
+// Specialization for float - print with full precision
+template<>
+void print_type<float>(OutputAdapter& out, const uint8_t* data) {
+  float value;
+  std::memcpy(&value, data, sizeof(float));
+  std::stringstream ss;
+  ss << std::setprecision(std::numeric_limits<float>::max_digits10);
+  ss << value;
+  out.write(ss.str());
+}
+
 // Unified print function for vector types
 template<typename T, size_t N>
 void print_vector(OutputAdapter& out, const uint8_t* data) {