v1.6.4 — Boxed Sections parser fix + structured WorkHistory/Education blocks

Bug fix + structured-block patch. Adds two new public Block types —
WorkHistoryBlock and EducationBlock — that let template authors
declare work-history and education entries with explicit (title,
organisation, date, description) / (degree, institution, year,
details) fields instead of relying on the legacy
MultiParagraphBlock pipe-separated string parser. Also closes a
Boxed Sections layout defect that bundled the date and description
into the right-aligned date column for any author-supplied line that
used an em-dash (" — "), en-dash (" – "), or contained
prose-shaped content the parser misread as a date. No public API
break — the sealed Block permit list grows from six to eight,
existing MultiParagraphBlock work-history strings continue to
parse, and the deprecated parser path stays in place for backward
compatibility.

Templates — new structured blocks

• WorkHistoryBlock. New public record block carrying a list of
  Item(title, organisation, date, description) entries. The
  BoxedSections preset renders each item as a structured row:
  title bold on the left, date right-aligned on the same row,
  organisation italic on the next line under the title, and
  description as a full-width paragraph beneath. Other presets fall
  back to a single concatenated paragraph per item. Authors who use
  WorkHistoryBlock bypass the legacy
  BoxedSections#parseWorkEntry heuristic parser entirely.
• EducationBlock. New public record block carrying a list of
  Item(degree, institution, year, details) entries. Renders with
  the same structured layout as WorkHistoryBlock (degree bold
  left, year right, institution italic, details paragraph) so
  Education & Certifications sections visually match Professional
  Experience.
• Sample data migrated. ExampleDataFactory.sampleCvSpecV2 now
  uses WorkHistoryBlock for Professional Experience and
  EducationBlock for Education & Certifications. The legacy
  MultiParagraphBlock pattern remains supported and is exercised
  by PresetLayoutSnapshotTest / PresetVisualParityTest to lock
  the backward-compat path.

Templates — parser robustness (legacy path)

• parseWorkEntry accepts em-dash and en-dash. Used to split
  the post-pipe segment on ASCII " - " only; now tries " — ",
  " – ", and " - " in order, mirroring splitHeading. Authors
  who typed "*2024-Present* — Led reusable document flows." saw
  the whole tail collapse into the date column — this no longer
  happens.
• parseWorkEntry rejects prose dressed up as a date. The
  loose looksLikeDate check accepted any string containing a
  year and a hyphen anywhere, which caused education lines like
  "... | 2019. First-class honours. Specialisation ..." to
  parse as work entries (the hyphen inside "First-class" was
  enough to satisfy the heuristic). Parser now rejects post-pipe
  segments that contain sentence-ending punctuation (., :,
  ;) when no explicit date / description separator was found,
  letting these lines fall back to plain paragraph rendering.
  Marked @Deprecated with a @deprecated Javadoc pointing
  callers to WorkHistoryBlock / EducationBlock.
• parseProjectItem picks up the same em-dash / en-dash /
  ASCII separator set so future Project items typed with em-dash
  don't regress into "title only" rendering.

Tests

• BlockTest.blockSealingPermitsAllEightVariants updated for the
  two new permitted block types.
• PresetVisualGalleryTest.sampleSpec migrated to
  WorkHistoryBlock so the visible "primary example" exercises the
  new structured shape.
• PresetLayoutSnapshotTest intentionally retained on
  MultiParagraphBlock to lock the legacy parser's behaviour.