Style docstrings with doc-builder; mark prompt strings docstyle-ignore
Reflow the Ideogram4 prompt-enhancer docstrings to the 119-col doc-builder
style, and add `# docstyle-ignore` to the functional `CAPTION_SYSTEM_MESSAGE`
and `CAPTION_USER_TEMPLATE` strings so the styler doesn't rewrap them (matching
Flux2's `system_messages.py`).