Add the Neutral template family, template picker and text-only logo allowances

Linea (the vendor's original format.pdf design), Monogram and Serenity are
rebuilt from the Canva PDFs as one parametric family on the engine, with
the user's logo in the measured slot, a home for every GST field and
A4/Letter support. Adds static Montserrat, Open Sans and Poppins fonts and
a generated Ms Madi outline for Serenity's vertical word. Text-only logo
placeholders (Monolith, Tangerine) use a doc-derived allowance box. A
Carbon TemplatePicker with committed thumbnails opens from the page
setup controls.

scripts/logo/measure-placeholders.mjs

@@ -39,6 +39,30 @@ const SEARCH_RECTS = {
   13: { id: "citrus-split", rect: { x: 325, y: 65, w: 165, h: 55 }, kind: "lockup", anchor: "left", vAlign: "middle", dark: false },
 };
 
+/*
+ * Allowances for text-only placeholders: the placeholder's own box (46.8 x 9 pt, 82.5 x 14.8 pt) would
+ * make a real logo unreadable, so the target box comes from the template docs and keeps the text's
+ * anchor edge.
+ *   monolith          docs/templates/03-monolith.md "Mapping to Voiced fields": 'CAVEIN' becomes the vendor logo,
+ *                     right-aligned, at most 28 pt tall so the 3-line stack keeps its 21 pt pitch (a 3:1 PNG is
+ *                     84 x 28); up to 160 wide, ending at the same right edge (x 560); top at the text's cap top.
+ *   tangerine-ledger  docs/templates/11-tangerine-ledger.md "Mapping": 'Rimberio' becomes the vendor logo, maxHeight 36
+ *                     at x 59.5, y about 62; up to 220 wide, left edge kept.
+ */
+const ALLOWANCES = {
+  monolith: { w: 160, h: 28, top: 54.75, vAlign: "top" },
+  "tangerine-ledger": { w: 220, h: 36, top: 62, vAlign: "middle" },
+};
+
+const r2 = (v) => Math.round(v * 100) / 100;
+
+/** The allowance box for a text-only slot: its width and height from the docs, anchored where the text is. */
+function allowanceBox(id, lockup, anchor) {
+  const a = ALLOWANCES[id];
+  const x = anchor === "right" ? lockup.x + lockup.w - a.w : lockup.x;
+  return { x: r2(x), y: a.top, w: a.w, h: a.h };
+}
+
 const TEMPLATE_IDS = [
   "classic", "marble", "highlighter", "monolith", "linea", "monogram", "serenity", "crimson-grid",
   "cobalt-stripe", "slate-band", "teal-swoosh", "tangerine-ledger", "purple-pop", "citrus-split",
@@ -125,8 +149,6 @@ function firstColumnGroup(mask, w, h, box) {
   return null;
 }
 
-const r2 = (v) => Math.round(v * 100) / 100;
-
 function toPt(rect, box) {
   return {
     x: r2(rect.x + box.minX / SCALE),
@@ -172,6 +194,7 @@ async function main() {
     }
 
     const rounded = (v) => Math.round(v * 1000) / 1000;
+    const textOnly = spec.kind === "text";
     slots[spec.id] = {
       page: { w: PAGE.w, h: PAGE.h },
       mark: markBox,
@@ -179,8 +202,10 @@ async function main() {
       markDensity: rounded(markDensity),
       lockupDensity: rounded(lockupDensity),
       anchor: spec.anchor,
-      vAlign: spec.vAlign,
+      vAlign: textOnly ? ALLOWANCES[spec.id].vAlign : spec.vAlign,
       darkSurface: spec.dark,
+      textOnly,
+      allowance: textOnly ? allowanceBox(spec.id, lockupBox, spec.anchor) : lockupBox,
     };
     rows.push({ n, id: spec.id, mark: markBox, lockup: lockupBox, markDensity, lockupDensity, anchor: spec.anchor, dark: spec.dark, bg });