Static analysis errors

[kmilos]

Interesting OpenScanHub output from Fedora's repository scan (it's for 0.25.3 currently, but these still apply to 0.26.0):

Error: CPPCHECK_WARNING ([CWE-398](https://cwe.mitre.org/data/definitions/398.html)): [[#def3]](https://svashisht.fedorapeople.org/openscanhub/mass-scans/f44-08-Jan-2026/openjph-0.25.3-2.fc44/scan-results.html#def3)
OpenJPH-0.25.3/src/apps/ojph_compress/ojph_compress.cpp:619: error[throwInEntryPoint]: Unhandled exception thrown in function that is an entry point.
#  617|       return -1;
#  618|     }
#  619|->   if (!get_arguments(argc, argv, input_filename, output_filename,
#  620|                        prog_order, profile_string, num_decompositions,
#  621|                        quantization_step, reversible, employ_color_transform,

Error: CPPCHECK_WARNING ([CWE-190](https://cwe.mitre.org/data/definitions/190.html)): [[#def4]](https://svashisht.fedorapeople.org/openscanhub/mass-scans/f44-08-Jan-2026/openjph-0.25.3-2.fc44/scan-results.html#def4)
OpenJPH-0.25.3/src/core/transform/ojph_colour.cpp:325: error[integerOverflow]: Signed integer overflow for expression '-2147483647-1'.
#  323|         float fl_low_lim = (float)neg_limit; // val >= lower
#  324|         si32 s32_up_lim = INT_MAX >> (32 - bit_depth);
#  325|->       si32 s32_low_lim = INT_MIN >> (32 - bit_depth);
#  326|   
#  327|         if (is_signed)

Error: CPPCHECK_WARNING ([CWE-190](https://cwe.mitre.org/data/definitions/190.html)): [[#def5]](https://svashisht.fedorapeople.org/openscanhub/mass-scans/f44-08-Jan-2026/openjph-0.25.3-2.fc44/scan-results.html#def5)
OpenJPH-0.25.3/src/core/transform/ojph_colour_avx2.cpp:293: error[integerOverflow]: Signed integer overflow for expression '-2147483647-1'.
#  291|         __m256 fl_low_lim = _mm256_set1_ps((float)neg_limit);  // val >= lower
#  292|         __m256i s32_up_lim = _mm256_set1_epi32(INT_MAX >> (32 - bit_depth));
#  293|->       __m256i s32_low_lim = _mm256_set1_epi32(INT_MIN >> (32 - bit_depth));
#  294|   
#  295|         if (is_signed)

Error: CPPCHECK_WARNING ([CWE-190](https://cwe.mitre.org/data/definitions/190.html)): [[#def6]](https://svashisht.fedorapeople.org/openscanhub/mass-scans/f44-08-Jan-2026/openjph-0.25.3-2.fc44/scan-results.html#def6)
OpenJPH-0.25.3/src/core/transform/ojph_colour_sse2.cpp:138: error[integerOverflow]: Signed integer overflow for expression '-2147483647-1'.
#  136|         __m128 fl_low_lim = _mm_set1_ps((float)neg_limit); // val >= lower
#  137|         __m128i s32_up_lim = _mm_set1_epi32(INT_MAX >> (32 - bit_depth));
#  138|->       __m128i s32_low_lim = _mm_set1_epi32(INT_MIN >> (32 - bit_depth));
#  139|   
#  140|         if (is_signed)

The first one is real, the others maybe not be worth all the casting hassle...?