Implement inline and block rendering semantics

[Matographo]

Summary

Add rendering behavior that clearly separates same-line substitution from multi-line control-flow output.

Why

Whitespace and newline correctness are critical for code generation and config-file rendering.

Acceptance Criteria

• Inline constructs stay on the current line unless the template says otherwise
• Block constructs preserve intended multi-line structure
• Behavior is documented and tested

Dependencies

• Depends on Specify the template language grammar #1
• Depends on Implement the recursive-descent parser for expressions and control flow #17