Better text fitting for template generation

Template-based generation is more aware of the difference between fixed template labels, story structure markers, and content that should be rewritten from your source.

That means new drafts from saved or system templates are less likely to overwrite template chrome such as step labels or button text when those elements should stay fixed.

Generated copy also has better fitting behavior for compact template slots. SlideDrift now prefers shorter complete thoughts over bluntly trimming text, so body copy is less likely to end mid-sentence or on dangling connector words.