test(templates): restore layout snapshot coverage for shipped presets

[DemchaAV]

Why

33 of the 58 shipped presets had no active layout-snapshot coverage: 16 CV presets, all 15
cover letters, ModernInvoice and ModernProposal. They were gated by pixel tests alone, and
those tolerate 50 000 mismatched pixels, so a shift of a few points in any of them passed
unseen. The suites that once pinned them were deleted along with older template families
(#276, #277, and the v1.6 cleanup 47241c83); their baselines stayed on disk and nothing
read them any more.

backup/template-fixtures-local-work-2026-09-11 held the missing test work, as one commit
on top of v2.2.0 with baselines rendered by v2.2.0. It was reimplemented on current develop
rather than cherry-picked: the fixtures and gates are built from develop's own code, and every
baseline was recorded on this tree.

What changed

• Coverage restored for 16 CV presets, 15 cover-letter presets, ModernInvoice and
  ModernProposal, through four gates:
  • CvPresetLayoutSnapshotTest and CoverLetterPresetLayoutSnapshotTest read
    CvPresetFixtures and CoverLetterPresetFixtures. Their roster and canonical document
    were moved verbatim out of the two pixel gates, so the pixel gate and the snapshot gate
    render the same presets on the same document. CoverLetterTextLayerGateTest reads the
    letter from its new home.
  • ProposalPresetLayoutSnapshotTest snapshots ModernProposal on the canonical proposal
    its pixel gate already renders.
  • InvoicePresetLayoutSnapshotTest reads a new InvoicePresetFixtures.layoutSnapshotPresets();
    canonicalInvoice(), stressInvoice() and their four consumers are unchanged.
    ClassicInvoice is not listed, because its own suite already pins it on the same invoice
    at the same margin.
• 33 current baselines added, named <pixel slug>_layout.
• ShippedPresetLayoutSnapshotCoverageTest: every shipped preset must be rendered by an
  active layout-snapshot suite. The shipped set comes from the templates sources (every
  presets class declaring a public ID), the covered set from the qa sources (presets an
  enabled assertCanonicalSnapshot suite creates directly or through a fixture roster). No
  count and no hand-kept list is asserted, so a preset added without a suite fails it by name.
  A reviewed exemption goes in an allow-list with its reason; the list is empty.
• 38 orphaned JSON snapshots removed, and 9 dead TemplateTestSupport helpers with
  their imports. Its javadoc now states the coverage rule.

Baseline safety

Every baseline was classified before any was recorded.

• The 33 current renders were compared with the backup's v2.2.0 baselines:
  19 identical, 14 different.
• All 14 were explained individually. Each difference was attributed to the develop commit it
  changes at, by rendering on either side of that commit:

Cause	Presets	What moved
#676, spaced caps set with tracking instead of padded strings	classic_serif, sidebar_portrait, mint_editorial, timeline_minimal (CV and letter); part of minimal_underlined, centered_headline, monogram_sidebar	heading and name widths only; no coordinate, height or page
d0c946ad (in #633), stacked rows drawn as lists	boxed_sections, minimal_underlined, modern_professional, executive, panel (4 fewer nodes each); blue_banner, centered_headline (node kind only)	bullet paragraphs become ListNodes
#577, the employer drawn in Monogram Sidebar entries	monogram_sidebar	2 added nodes
361ff833 (in #633), a box no longer opens on a page its first unit cannot start on	modern_proposal	one empty wrapper node

• C = 0. No suspicious change was found, and no unexplained baseline was accepted.
  Page counts are unchanged in all 14, and every node that moved still sits inside its parent
  and inside the page's content band.
• The recorded baselines are byte-identical to the renders that were analysed (33 / 33), and
  the 19 identical presets are byte-identical to the backup's baselines too (19 / 19).

ModernProposal is an engine bookkeeping fix, not a pagination regression. The footer note
needs 23.25pt and 15.49pt were left under the acceptance terms. Its paragraph, the only thing
the footer draws, was therefore already on page 1 at v2.2.0, at y 790.64 (the second page;
snapshots count pages from 0). Only ProposalV2ModernFooter[6], the empty page-flow wrapper
around it, still claimed page 0 at y 20.24. It now sits with its paragraph on page 1. Page
count 2 and node count 43 are unchanged, nothing drawn moved, and the pixel baseline recorded
before v2.2.0 still passes.

Coverage

Family	Covered
cv	26 / 26
coverletter	15 / 15
invoice	11 / 11
proposal	4 / 4
receipt	1 / 1
rota	1 / 1
total	58 / 58
uncovered	0

On develop before this branch: 25 / 58.

Verification

• 4 new layout-snapshot gates: 33 / 33
• affected pixel gates green: CV 16, cover letter 15, invoice 2, proposal 1
• affected text-layer gates green: CV 52, cover letter 16, invoice 12, proposal 5
• every *LayoutSnapshotTest in qa plus the coverage test: 74 green
• templates module: 127 green
• qa module: 1759 green
• ./mvnw -B -ntp clean verify: BUILD SUCCESS, 15 / 15 modules, 3258 tests, 0 failures,
  0 errors (2 skipped: the pre-existing POSIX assumptions in FileOutputSafetyTest). That is
  develop's 3223 plus the 33 gate tests and the 2 coverage tests.
• each of the first three commits verified green on its own
• git diff --check clean

The coverage test was sabotaged and went red each time, naming the right preset: the four new
gates removed (it names exactly the 33), a preset dropped from a roster, a new preset class
with no suite, a suite disabled by a fully qualified @Disabled or no longer calling
assertCanonicalSnapshot, a suite that reads a fixture only for its document, and stale
allow-list entries.

Scope

• no production code changed
• no public API changed
• no pixel baseline changed
• no documentation changed
• backup/template-fixtures-local-work-2026-09-11 was not modified
• this branch is not merged

Lane: test (qa only).