Use inline style for text bold/font in SVG export (Ignition compat)

Ignition strips font-weight/font-family/font-size as separate SVG
attributes but preserves them inside style="..." CSS. Moved all text
styling to inline style for conveyance labels and BCN/SOL/PDP symbols.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

svelte-app/src/lib/export.ts

@@ -73,7 +73,7 @@ function emitConveyanceLabelInner(lines: string[], sym: PlacedSymbol) {
   for (let i = 0; i < textLines.length; i++) {
     const dy = -(textLines.length - 1) * lineH / 2 + i * lineH;
     const y = labelCy + dy + fontSize * 0.35;
-    lines.push(`    <text x="${labelCx}" y="${y}" text-anchor="middle" font-family="Arial" font-weight="bold" font-size="${fontSize}px" fill="#000000"${rotAttr}>${textLines[i]}</text>`);
+    lines.push(`    <text x="${labelCx}" y="${y}" text-anchor="middle" style="font-family:Arial;font-weight:bold;font-size:${fontSize}px;fill:#000000"${rotAttr}>${textLines[i]}</text>`);
   }
 }