fix: Remove commented-out code violating coding standards

[krystophny]

DEFECT: Commented-out code found in codebase

Category: TECHNICAL-DEBT
Severity: MINOR

Description

Commented-out code violates our mandatory coding standards which explicitly state 'NO commented-out code'.

Files with violations:

• src/fortplot_3d_axes.f90:188 - Commented call to draw_3d_axis_ticks_and_labels
• src/fortplot.f90:550 - Commented boxplot call
• src/fortplot_ascii.f90:140 - Commented if statement

Required Action

Remove all commented-out code. These lines serve no purpose and violate our code cleanliness standards.

Impact

• Violates KISS principle (unnecessary complexity)
• Creates confusion about whether code is needed
• Violates immediate cleanup policy

[krystophny]

Resolved by commit 4e8b782. All commented-out code removed to comply with coding standards:

✅ fortplot_3d_axes.f90:188: Removed commented call to draw_3d_axis_ticks_and_labels

• Kept informative TODO comment explaining what needs implementation
• Removed unnecessary commented function call

✅ fortplot.f90:550-551: Removed commented boxplot call

• Kept TODO comment about implementing boxplot method in figure_core
• Removed multi-line commented function call

✅ fortplot_ascii.f90:140-141: Removed commented debug block

• Removed empty commented if statement used for debugging
• Cleaned up debug scaffolding that served no purpose

Impact:

• ✅ Code now complies with mandatory 'NO commented-out code' standard
• ✅ Follows KISS principle by removing unnecessary complexity
• ✅ Eliminates confusion about whether code is actually needed
• ✅ Adheres to immediate cleanup policy
• ✅ All tests pass - no functional regressions

The codebase is now cleaner and follows the established coding standards without any functional impact.