refactor(non-verbal): eliminate parallel TS projection (TODO.figures/19 Option A)

[ronaldtse]

Closes TODO.figures/19 Step 7 Option A.

What

Removes the parallel TypeScript projection of the non-verbal hierarchy.
Bridges now return glossarist-js class instances (new Figure(...),
new Table(...), new Formula(...), new FigureImage(...)) instead of
plain { \$kind: 'figure', ... } literals, and components narrow via
instanceof / property access against the upstream classes.

Why

The consumer's adapters/non-verbal/types.ts previously redeclared every
class shape as a TS interface — a parallel projection of the upstream model.
Every shape change in glossarist-js required a corresponding edit here, and
the two definitions could silently drift. With this refactor the upstream
classes become the single source of truth at the type layer; this repo only
owns what is genuinely consumer-side (wire shapes parsed by the bridges,
plus the local string-union refinements).

Slimmed types.ts to consumer-only types

Kept:

• LocalizedString, NonVerbalKind — routing/anchor/mention discriminator
• FigureImageFormat, FigureImageRole, TableFormat, FormulaNotation —
  validated string unions the bridges check at parse time
• NonVerbalSource* — wire shape for JSON-LD source entries
• TableContent — discriminated union the TableDisplay component switches on
• NonVerbRepV3, NonVerbRepImage — local view of NonVerbRep's V3 runtime
  shape (upstream .d.ts still pre-V3, see chore(types): declare NonVerbal classes in models/index.d.ts glossarist-js#31)
• NonVerbalReference — inline mention routing shape

Removed (sourced from glossarist):

• Figure, Table, Formula, FigureImage
• NonVerbalEntity, NonVerbalEntityBase

Component updates

• FigureImages accepts ImageLike = FigureImage | NonVerbRepImage so the
  same component works for class instances (Figure) and plain objects
  (NonVerbRep). Nullable-safe accessors (imgSrc, imgFormat, imgRole)
  paper over the T | null upstream convention.
• Props accept T | null throughout (upstream convention) instead of
  T | undefined. Resolvers receive ?? undefined at the call site.
• NonVerbalSources takes upstream ConceptSource[] directly. The old
  asCitation shim is gone — src.origin is already Citation | null.
• TableDisplay casts table.content to the consumer's TableContent
  union. Upstream keeps it as Record<string, unknown> because the
  structured/markup split is a consumer concern.
• FormulaDisplay casts formula.notation to FormulaNotation.

Temporary module augmentation

Added src/adapters/non-verbal/glossarist-augment.d.ts. Upstream's
published .d.ts (v0.4.2) re-exports Figure / Table / Formula from
index.d.ts, but the underlying models/index.d.ts declares none of them,
so TypeScript silently resolves consumer imports to any. The local
augmentation restores type safety until PR glossarist/glossarist-js#31
ships in v0.4.3+. Deletion marker is in the file header.

Verification

• npx vue-tsc --noEmit — 0 errors
• npm test — 797 passed, 1 skipped
• npm run check:scripts — syntax OK on 14 files