Problem

No way to set page margins via the CLI today. After gog docs write --replace --markdown --pageless, margins stay at the default 72pt (1″) all around — too generous for pageless docs with wide tables.

Repro (v0.18.0)

gog docs write --help | grep -iE "margin|width"
# (no margin / width flags)

gog docs page-layout --help | grep -iE "margin"
# (no margin flags)

Proposed fix

Add --margin-left=<PT>, --margin-right=<PT>, --margin-top=<PT>, --margin-bottom=<PT> to docs write and docs page-layout. Accept either points or inches (--margin-left=0.5in).

Why it matters

Companion to #629 (pageSize widening). Both are needed for pageless docs with wide tables. Today users post-process via Docs API updateDocumentStyle — same call surface a CLI flag would wrap.

v0.18.0 verified

• No margin flags on docs write, docs update, or docs page-layout.