fix(templates): draw the employer in Monogram Sidebar experience entries

[DemchaAV]

Stacked on #576 — retarget to develop once that merges.

Why

MonogramSidebar.addExperienceEntries rendered entry.title(), entry.date() and
entry.body() and never entry.subtitle(). In an experience section the subtitle is the
employer, so every company name was missing from the rendered CV. The education path in
the same preset does render its subtitle, which is what made the gap look accidental
rather than chosen.

Separately, three presets drop content without saying so. MonogramSidebar,
SidebarPortrait and MintEditorial each cap their blocks — a caller with four jobs who
picks one of them gets two, and nothing in the API or the produced PDF reports it.

What changed

The employer is drawn between the position and the date, in theme.entrySubtitleStyle()
— the shared theme style, not a preset-local one.

Each of the three presets documents its own caps, and the gallery
(docs/templates/v2-layered/using-templates.md) carries the same table under Picking a
preset.

The caps themselves are unchanged, and the documentation says why. Each preset builds
its columns as one addRow, which is atomic: it fits a page whole or the paginator raises
AtomicNodeTooLargeException. Removing every cap and rendering a dense CV through the
three presets reproduces that immediately — MonogramSidebar asks for 1043pt of an
841pt page, SidebarPortrait 1157pt, MintEditorial 894pt of 745pt — and it does so at
two experience entries, because the skill and education caps are load-bearing too. So
lifting them does not paginate; it turns a CV that silently lost an entry into one that
fails to render. Doing it properly means teaching each preset to pick its own page
boundaries, the way TimelineMinimal does with ColumnPagination — which that helper
cannot serve as written, since it models flattened text blocks and these presets carry a
monogram ring, an SVG contact stack, a portrait and skill bars.

Verification

./mvnw -B -ntp clean verify -pl :graph-compose-core,:graph-compose-render-pdf,:graph-compose-render-docx,:graph-compose-render-pptx,:graph-compose-templates,:graph-compose-testing,:graph-compose-qa,:graph-compose-coverage -am — BUILD SUCCESS, 762 qa tests.
./mvnw -B -ntp javadoc:javadoc -pl :graph-compose-core,:graph-compose-templates — BUILD SUCCESS.

• MonogramSidebarContentFidelityTest (qa, 2 tests) pins that an experience entry names
  its employer, and that the entry past the documented cap is the only one missing. Both
  go red without this change.
• One visual baseline (cv-v2-layered/monogram_sidebar-page-0.png) and one committed
  preview (cv-monogram-sidebar-v2.pdf) carry the extra line; the drift gate names no
  others.