SVG fonts are theme defaults, not the model's: QEA builder drops font_size, elements render Arial 9px/13px instead of EA fonts

[ronaldtse]

Summary

Emitted SVG text does not use the fonts specified by the model. The emitter always renders theme defaults (observed: Arial 9px, Yu Gothic UI 13px, Calibri 7px mixed in one diagram), while EA's own export applies the per-element font face and size. Font face and size therefore differ from what EA builds.

Mechanism

Ea::Model::DiagramElement models the full font set (font_family, font_size, font_bold, font_italic, font_underline), but:

1. The QEA builder drops the size. lib/ea/sources/qea/diagram_builder.rb:95-97 maps only font_family, font_bold, font_italic from the style hash — font_size and font_underline are never assigned. The QEA style/font table carries the size (EA stores per-element font size); it is parsed into style_hash and discarded.
2. FontResolver therefore always misses. lib/ea/svg/ea_emitter/font_resolver.rb:35-43 uses element.font_size only when explicitly set, else falls back to theme.font_size — so every element renders at the theme default instead of its model font.
3. Serialized diagram shards confirm it: elements carry fontFamily / fontBold / fontItalic but no fontSize key at all.

Result in one rendered CG2 diagram: font-family:Arial; font-size:9px (×42), Yu Gothic UI 13px (×21), Calibri 7px (×1) — a theme mishmash, not the model's fonts, and px units where EA's export uses its own font-size conventions.

Impact

Any consumer comparing our SVG to EA's export sees wrong text metrics: different face, different size, different line wrapping and box overflow. This blocks the parity goal — SVG output must be fully identical to what EA builds — together with #51 (text renderer crash) and #52 (connector source ports).

Suggested direction

• QEA diagram_builder: map font_size (and font_underline) from the style hash / font table alongside family/bold/italic; consult the QEA font table (t_font) where per-object overrides live.
• Keep FontResolver's theme fallback, but only for elements that genuinely have no font data.
• Add font face/size/weight to Ea::Svg::Parity::Checker's measured attributes so regressions are caught against EA reference exports.

Parity acceptance

Parity::Suite (lib/ea/svg/parity/suite.rb) is ready to drive this — it compares our render against per-diagram EA reference SVGs (<eaid>.svg in a reference dir) — but the repository currently ships zero EA reference exports. To "ensure the SVGs built are fully identical to what EA builds", we need a set of EA-exported reference SVGs for a representative diagram subset committed as fixtures, and the suite extended to fail on font/geometry deltas, not just element counts.