refactor(sonar): assorted small fixes

- empty() instead of size() comparisons (cpp:S1155)
- member initialisers in declaration order (cpp:S3229)
- no redundant c_str() when a std::string is accepted (cpp:S7121)
- contains() on associative containers (cpp:S6171)
- const reference instead of a copying range-for (cpp:S6032)
- starts_with() for prefix checks (cpp:S6178)
- no std::move on temporaries (cpp:S5274)
- has_value() on std::optional (cpp:S7172)
- bool literals for bool members (cpp:S5820)
- inline only on the definition (cpp:S3548)
- explicit base access specifier (cpp:S5965)
- explicit element access instead of dereferencing an array (cpp:S7116)
- rely on the C++20 rewritten operator!= (cpp:S6186)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

utilities/Float3d.h

@@ -245,7 +245,7 @@ public:
             e[i + 2] = f; // zamiana Y i Z
         }
     };
-    inline float4x4 &Rotation(float const angle, float3 const &axis);
+    float4x4 &Rotation(float const angle, float3 const &axis);
     inline bool IdentityIs() const
     { // sprawdzenie jednostkowości
         for (int i = 0; i < 16; ++i)