feat(agents): добавлены skills для PDF, docs, slides, jupyter и spreadsheet

- Зачем:
  - расширены возможности AI-ассистентов для работы с документами и презентациями
- Что:
  - добавлен skill pdf для работы с PDF файлами
  - добавлен skill doc для работы с Word документами
  - добавлен skill slides для создания презентаций PowerPoint
  - добавлен skill jupyter-notebook для работы с Jupyter ноутбуками
  - добавлен skill spreadsheet для работы с таблицами (Excel/CSV)
  - изменена модель Claude с sonnet на opus
- Проверка:
  - проверка доступности skills в AI-ассистентах

agents/.agents/skills/slides/assets/pptxgenjs_helpers/text.js

@@ -0,0 +1,789 @@
+// Copyright (c) OpenAI. All rights reserved.
+"use strict";
+
+const { spawnSync } = require("child_process");
+const { Canvas } = require("skia-canvas");
+// Unicode line-break iterator (UAX #14) so we mimic PPT/LibreOffice wrapping rules.
+const LineBreaker = require("linebreak");
+const fontkit = require("fontkit");
+const TEXT_MEASURER = getTextMeasurer();
+const registeredFontVariants = new Set();
+const fontPathCache = new Map();
+const fontKitCache = new Map();
+
+// Estimate the text box height for a given font size and line count.
+// NOTE: This is an analytical approximation, not an exact reproduction of
+// PowerPoint/LibreOffice layout. Always verify visually and adjust based on
+// actual rendering if precise fit is required.
+function calcTextBoxHeightSimple(
+  fontSize,
+  lines = 1,
+  leading = 1.15,
+  padding = 0.3
+) {
+  const lineHeightIn = (fontSize / 72) * leading;
+  return lines * lineHeightIn + padding;
+}
+
+// Compute font size that fits given text within a fixed box.
+// NOTE: autoFontSize uses skia-canvas measurement stack to approximate the font size
+// that will fit in a given box. Rendering engines may differ slightly, so
+// treat the result as an estimate and tweak as needed after visual inspection.
+// Signature:
+//   autoFontSize(textOrRuns, fontFace, opts?)
+//   - fontFace must be provided as the 2nd positional argument and cannot be in opts.
+//   - All modes always respect [minFontSize, maxFontSize] as a CLOSED interval when provided.
+// Modes:
+//   - mode: "shrink"  => shrink only (search [minFontSize, min(maxFontSize, fontSize)])
+//   - mode: "enlarge" => enlarge only (search [max(minFontSize, fontSize), maxFontSize])
+//   - mode: "auto"    => shrink + enlarge (search [minFontSize, maxFontSize]); fontSize optional.
+// In "auto" mode fontSize is not required; when omitted we simply search the whole [minFontSize, maxFontSize] range.
+// Returns a cloned options object with computed fontSize. fit: "shrink" is appended only when mode === "shrink".
+function autoFontSize(textOrRuns, fontFace, opts = {}) {
+  const x = toNumber(opts.x, 0);
+  const y = toNumber(opts.y, 0);
+  const w = toNumber(opts.w, 0);
+  const h = toNumber(opts.h, 0);
+  if (!(w > 0 && h > 0)) throw new Error("autoFontSize(): non-positive w or h");
+
+  const face = typeof fontFace === "string" ? fontFace.trim() : "";
+  if (face.length === 0) {
+    throw new Error(
+      "autoFontSize(): fontFace is required as the 2nd positional argument."
+    );
+  }
+
+  // Fast-path: if there is no visible text content, just return the
+  // (optionally clamped) reference fontSize; there is nothing to fit.
+  const hasAnyText =
+    normalizeText(textOrRuns).trim().length > 0 ||
+    (Array.isArray(textOrRuns) &&
+      textOrRuns.some(
+        (run) => run && typeof run.text === "string" && run.text.trim().length
+      ));
+
+  const fontStyle =
+    opts.italic === true || opts.fontStyle === "italic" ? "italic" : "normal";
+  const fontWeight =
+    opts.bold === true || String(opts.fontWeight || "").toLowerCase() === "bold"
+      ? "bold"
+      : "normal";
+  const leading = toNumber(opts.leading, 1.15) || 1.15;
+
+  const modeRaw = typeof opts.mode === "string" ? opts.mode : "auto"; // 'auto' (default) | 'shrink' | 'enlarge'
+  const mode = modeRaw.toLowerCase();
+  const isShrink = mode === "shrink";
+  const isEnlarge = mode === "enlarge";
+  const isAuto = mode === "auto";
+
+  const refPtRaw = toNumber(opts.fontSize, NaN);
+  const hasRefPt = Number.isFinite(refPtRaw);
+  const refPt = hasRefPt ? refPtRaw : NaN;
+
+  // Base bounds (closed interval). Defaults:
+  //   - minFontSize: 1pt
+  //   - maxFontSize: 1000pt (unless the caller provided a tighter bound)
+  let minPt = toNumber(opts.minFontSize, NaN);
+  let maxPt = toNumber(opts.maxFontSize, NaN);
+  const userProvidedMax = Number.isFinite(maxPt);
+  if (!Number.isFinite(minPt)) {
+    minPt = 1;
+  }
+  if (!Number.isFinite(maxPt)) {
+    maxPt = 1000;
+  }
+
+  if (isShrink || isEnlarge) {
+    if (!hasRefPt) {
+      throw new Error(
+        "autoFontSize(): mode 'shrink' or 'enlarge' requires fontSize"
+      );
+    }
+  }
+
+  if (isShrink) {
+    // Shrink only: never exceed the requested size (and respect maxFontSize).
+    maxPt = Math.min(maxPt, refPt);
+  } else if (isEnlarge) {
+    // Enlarge only: never go below the requested size (and respect minFontSize).
+    minPt = Math.max(minPt, refPt);
+  } else if (isAuto && hasRefPt && userProvidedMax) {
+    // Auto mode with an explicit maxFontSize: honor [minFontSize, maxFontSize]
+    // as the search band while allowing both shrink and enlarge within it.
+  } else if (!isAuto) {
+    throw new Error(
+      `autoFontSize(): unsupported mode "${modeRaw}", expected "auto" | "shrink" | "enlarge"`
+    );
+  }
+
+  if (!(maxPt > 0 && maxPt >= minPt)) {
+    throw new Error(
+      "autoFontSize(): invalid minFontSize/maxFontSize bounds after normalization"
+    );
+  }
+
+  // If there is no actual text, we can skip measurement entirely and just
+  // clamp the reference size to [minPt, maxPt].
+  if (!hasAnyText) {
+    const chosen =
+      (hasRefPt && Math.max(minPt, Math.min(maxPt, refPt))) || minPt;
+    const out = { ...opts, x, y, w, h, fontSize: chosen };
+    if (isShrink) out.fit = "shrink";
+    return out;
+  }
+
+  // Search the space of candidate font sizes with a small step and a safety
+  // bias baked into the fit test:
+  //   - precision: 0.05pt (~1/20pt) so we land very close to the true max-fit.
+  //   - safetyFactor: we require that the calcTextBox()-measured height is
+  //     within a small margin of the caller-provided box height, so that the
+  //     same layout engine used by calcTextBox drives autoFontSize decisions.
+  const precision = 0.05; // point precision for search (~1/20pt)
+  const safetyFactor = 0.97;
+
+  let lo = minPt;
+  let hi = maxPt;
+  let best = lo;
+  while (hi - lo > precision) {
+    const mid = (lo + hi) / 2;
+    // Delegate measurement to calcTextBox so that autoFontSize and
+    // calcTextBox share the exact same layout pipeline (paragraph modeling,
+    // bullet handling, margins, padding, width scaling, etc.).
+    const layout = calcTextBox(mid, {
+      text: textOrRuns,
+      w,
+      fontFace: face,
+      fontStyle,
+      fontWeight,
+      leading,
+      margin: opts.margin,
+      padding: opts.padding,
+      paraSpaceAfter: opts.paraSpaceAfter,
+    });
+    const fits = layout.h <= h * safetyFactor + 1e-6;
+    if (fits) {
+      best = mid;
+      lo = mid; // try larger
+    } else {
+      hi = mid; // shrink
+    }
+  }
+  // Closed interval: clamp to [minPt, maxPt].
+  const finalPt = Math.max(minPt, Math.min(maxPt, best));
+
+  // Pass through all original options, override fontSize and append fit: "shrink"
+  const out = { ...opts, x, y, w, h, fontSize: finalPt };
+  if (isShrink) out.fit = "shrink";
+  return out;
+}
+
+// Calculate text box metrics using skia-canvas measurement (lines, height,
+// width) for a given font size and text payload.
+// NOTE: calcTextBox approximates how many lines and how much space text will
+// occupy using our JS measurement pipeline. It is designed to be close to
+// PowerPoint/LibreOffice but is not guaranteed pixel-perfect—always adjust
+// based on actual slide rendering when precision matters.
+// Signature:
+//   calcTextBox(fontSizePt, opts)
+//     - fontSizePt: number (points)
+//     - opts (keywords): {
+//         text?: string | runs[],
+//         w?: number (inches),
+//         h?: number (inches),
+//         lines?: number,
+//         fontFace?: string, // required when measuring by width/height with text
+//         fontStyle?: 'normal' | 'italic', italic?: boolean,
+//         fontWeight?: 'normal' | 'bold', bold?: boolean,
+//         leading?: number (line height multiplier, default 1.15),
+//         padding?: number (inches, default 0.3),
+//         paraSpaceAfter?: number (points, default 0)
+//       }
+// Modes (auto-detected):
+//   a) Given lines -> compute height
+//   b) Given width + text -> compute height and lines
+//   c) Given height + text -> compute width and lines
+// Throws when insufficient info is provided.
+function calcTextBox(fontSizePt, opts = {}) {
+  const textInput = opts.text ?? "";
+  const text = normalizeText(textInput || "");
+  const face =
+    typeof opts.fontFace === "string" && opts.fontFace.trim().length > 0
+      ? opts.fontFace.trim()
+      : "";
+  const fontStyle =
+    opts.italic === true || opts.fontStyle === "italic" ? "italic" : "normal";
+  const fontWeight =
+    opts.bold === true || String(opts.fontWeight || "").toLowerCase() === "bold"
+      ? "bold"
+      : "normal";
+  const leading = toNumber(opts.leading, 1.15) || 1.15;
+  const padding = toNumber(opts.padding, 0.3); // inches (allow 0)
+  const paraSpaceAfterPt = toNumber(opts.paraSpaceAfter, 0) || 0; // points
+  const lineHeightIn = (fontSizePt / 72) * leading;
+  const margins = normalizeMargins(opts.margin);
+  const measurer = TEXT_MEASURER;
+
+  const hasLines = Number.isFinite(toNumber(opts.lines, NaN));
+  const hasWidth = Number.isFinite(toNumber(opts.w, NaN));
+  const hasHeight = Number.isFinite(toNumber(opts.h, NaN));
+  const paragraphs = buildParagraphModels(textInput, {
+    fontSizePt,
+    // Do not silently substitute a default font here; callers measuring by
+    // width/height are required to pass an explicit fontFace so that our
+    // metrics match the actual slide theme.
+    fontFace: face,
+    fontStyle,
+    fontWeight,
+    leading,
+    paraSpaceAfterPt,
+  });
+  const hasAnyText = paragraphs.some((p) => p.text.length > 0);
+
+  // Empirical top inset: PPT text frames render a small gutter above the first line
+  // even with zero margins. Model it as a fraction of the font size so callers can
+  // visually trim by shifting y up and growing h by the same amount.
+  const topInsetIn = (fontSizePt / 72) * 0.2; // ~20% of font size (inches)
+
+  if (hasLines) {
+    // Mode (a): Given lines -> compute height only
+    const lines = toNumber(opts.lines, 1);
+    const contentH = Math.max(0, lines * lineHeightIn + padding);
+    const h = contentH + margins.top + margins.bottom;
+    const passthrough = buildPassthroughOptions(opts, fontSizePt, margins);
+    return {
+      ...passthrough,
+      w: toNumber(opts.w, NaN) || null,
+      h,
+      lines,
+      contentH,
+      margins,
+      topInset: topInsetIn,
+    };
+  }
+
+  if (hasWidth && hasAnyText) {
+    // Mode (b): Given width + text -> compute height and lines
+    if (face.length === 0) {
+      throw new Error(
+        "calcTextBox(): opts.fontFace is required when measuring by width."
+      );
+    }
+    const boxW = toNumber(opts.w, 0);
+    if (!(boxW > 0))
+      throw new Error("calcTextBox(): width must be > 0 in mode 'width'");
+    const innerW = Math.max(0, boxW - margins.left - margins.right);
+    const { lines, heightIn } = layoutGivenWidth(paragraphs, innerW);
+    const contentH = Math.max(0, heightIn + padding);
+    const h = contentH + margins.top + margins.bottom;
+    const passthrough = buildPassthroughOptions(opts, fontSizePt, margins);
+    return {
+      ...passthrough,
+      w: boxW,
+      h,
+      lines,
+      contentH,
+      margins,
+      topInset: topInsetIn,
+    };
+  }
+
+  if (hasHeight && hasAnyText) {
+    // Mode (c): Given height + text -> compute minimal width and lines to fit
+    if (face.length === 0) {
+      throw new Error(
+        "calcTextBox(): opts.fontFace is required when measuring by height."
+      );
+    }
+    const boxH = toNumber(opts.h, 0);
+    if (!(boxH > 0))
+      throw new Error("calcTextBox(): height must be > 0 in mode 'height'");
+    const innerH = Math.max(0, boxH - margins.top - margins.bottom);
+    // Upper bound: single-line width across paragraphs
+    const singleLineWidth = paragraphs.reduce((mx, p) => {
+      const width = measureRunWidth(p, p.text) + p.textIndentIn;
+      return Math.max(mx, width);
+    }, 0);
+    const minHeightOneLine = Math.max(
+      0,
+      paragraphs.reduce((sum, p, idx) => {
+        const lineHeight = (p.fontSizePt / 72) * p.leading;
+        sum += lineHeight;
+        if (idx !== paragraphs.length - 1) sum += p.paraSpaceAfterIn;
+        return sum;
+      }, 0)
+    );
+    if (minHeightOneLine + padding - innerH > 1e-6) {
+      throw new Error(
+        "calcTextBox(): height too small for one-line layout at this font size"
+      );
+    }
+    // Lower bound: longest token width
+    const longestTokenWidth = paragraphs.reduce((mx, p) => {
+      const tokens = splitTextIntoTokens(p.text);
+      for (const tk of tokens) {
+        if (tk.length === 0) continue;
+        const wIn = measureRunWidth(p, tk) + p.textIndentIn;
+        if (wIn > mx) mx = wIn;
+      }
+      return mx;
+    }, 0);
+    let lo = Math.max(0.01, longestTokenWidth);
+    let hi = Math.max(lo, singleLineWidth);
+    let best = hi;
+    for (let iter = 0; iter < 32; iter++) {
+      const mid = (lo + hi) / 2;
+      const { lines, heightIn } = layoutGivenWidth(paragraphs, mid);
+      const totalH = heightIn + padding;
+      if (totalH <= innerH + 1e-6) {
+        best = mid;
+        hi = mid;
+      } else {
+        lo = mid;
+      }
+    }
+    const { lines, heightIn } = layoutGivenWidth(paragraphs, best);
+    const contentH = heightIn + padding;
+    const passthrough = buildPassthroughOptions(opts, fontSizePt, margins);
+    return {
+      ...passthrough,
+      w: best + margins.left + margins.right,
+      h: contentH + margins.top + margins.bottom,
+      lines,
+      contentH,
+      margins,
+      topInset: topInsetIn,
+    };
+  }
+
+  throw new Error(
+    "calcTextBox(): insufficient information. Provide {lines} or ({w,text}) or ({h,text})."
+  );
+}
+
+function layoutGivenWidth(paragraphs, boxW) {
+  let totalLines = 0;
+  let heightIn = 0;
+  for (let i = 0; i < paragraphs.length; i++) {
+    const para = paragraphs[i];
+    const widthScale = getWidthScaleForParagraph(para);
+    const usableWidth = Math.max(0.01, boxW - para.textIndentIn) * widthScale;
+    const lines = greedyWrap(para, usableWidth);
+    const count = Math.max(1, lines.length);
+    totalLines += count;
+    const lineHeightIn = (para.fontSizePt / 72) * para.leading;
+    heightIn += count * lineHeightIn;
+    if (i !== paragraphs.length - 1) heightIn += para.paraSpaceAfterIn;
+  }
+  return { lines: totalLines, heightIn };
+}
+
+function greedyWrap(paragraph, maxWidthIn) {
+  const text = paragraph.text || "";
+  if (text.length === 0) return [""];
+  const breaker = new LineBreaker(text);
+  const breakpoints = [];
+  let bk;
+  while ((bk = breaker.nextBreak())) {
+    breakpoints.push({ pos: bk.position, required: bk.required });
+  }
+  const lines = [];
+  let start = skipTextWhitespace(text, 0);
+  let idx = 0;
+  while (start < text.length) {
+    while (idx < breakpoints.length && breakpoints[idx].pos <= start) idx++;
+    let chosen = null;
+    let probe = idx;
+    while (probe < breakpoints.length) {
+      const br = breakpoints[probe];
+      const slice = text.slice(start, br.pos);
+      const width = measureRunWidth(paragraph, trimLineEnd(slice));
+      if (width <= maxWidthIn + 1e-6) {
+        chosen = br;
+        probe++;
+        if (br.required) break;
+      } else {
+        break;
+      }
+    }
+    if (!chosen) {
+      const forced = forceBreakSegment(text, start, maxWidthIn, paragraph);
+      if (forced.segment.length === 0) break;
+      lines.push(trimLineEnd(forced.segment));
+      start = skipTextWhitespace(text, forced.nextIndex);
+      continue;
+    }
+    const lineText = text.slice(start, chosen.pos);
+    lines.push(trimLineEnd(lineText));
+    start = skipTextWhitespace(text, chosen.pos);
+  }
+  if (!lines.length) lines.push("");
+  return lines;
+}
+
+function splitTextIntoTokens(text) {
+  if (typeof text !== "string") return [""];
+  const tokens = text.split(/(\s+)/);
+  return tokens.length ? tokens : [""];
+}
+
+function trimLineEnd(value) {
+  return typeof value === "string" ? value.replace(/\s+$/u, "") : "";
+}
+
+function measureRunWidth(paragraph, text) {
+  if (!text || text.length === 0) return 0;
+  const fontData = getFontData(
+    paragraph.fontFace,
+    paragraph.fontStyle,
+    paragraph.fontWeight
+  );
+  if (fontData && fontData.font) {
+    const layout = fontData.font.layout(text);
+    const widthPts =
+      (layout.advanceWidth / fontData.font.unitsPerEm) * paragraph.fontSizePt;
+    return Math.max(0, widthPts / 72);
+  }
+  return TEXT_MEASURER(
+    text,
+    paragraph.fontSizePt,
+    paragraph.fontFace,
+    paragraph.fontStyle,
+    paragraph.fontWeight
+  );
+}
+
+function forceBreakSegment(text, start, maxWidthIn, paragraph) {
+  const chars = Array.from(text.slice(start));
+  if (chars.length === 0) return { segment: "", nextIndex: text.length };
+  let buffer = "";
+  let consumedUnits = 0;
+  for (let i = 0; i < chars.length; i++) {
+    const candidate = buffer + chars[i];
+    const width = measureRunWidth(paragraph, trimLineEnd(candidate));
+    if (width <= maxWidthIn + 1e-6) {
+      buffer = candidate;
+      consumedUnits += chars[i].length;
+      continue;
+    }
+    if (buffer.length === 0) {
+      buffer = chars[i];
+      consumedUnits += chars[i].length;
+    }
+    break;
+  }
+  if (buffer.length === 0) {
+    buffer = chars[0] || "";
+    consumedUnits = buffer.length;
+  }
+  return { segment: buffer, nextIndex: start + consumedUnits };
+}
+
+function skipTextWhitespace(text, index) {
+  let idx = index;
+  while (idx < text.length && /\s/.test(text[idx])) idx++;
+  return idx;
+}
+
+function buildParagraphModels(textOrRuns, baseStyle) {
+  const entries = collectParagraphEntries(textOrRuns);
+  if (entries.length === 0) {
+    return [resolveParagraphStyle({ text: "" }, baseStyle)];
+  }
+  return entries.map((entry) => resolveParagraphStyle(entry, baseStyle));
+}
+
+function collectParagraphEntries(textOrRuns) {
+  const result = [];
+  if (Array.isArray(textOrRuns)) {
+    for (const entry of textOrRuns) {
+      if (typeof entry === "string") {
+        pushParagraphSegments(entry, undefined, result);
+      } else if (entry && typeof entry === "object") {
+        pushParagraphSegments(entry.text ?? "", entry.options || {}, result);
+      }
+    }
+    return result;
+  }
+  pushParagraphSegments(textOrRuns ?? "", undefined, result);
+  return result;
+}
+
+function pushParagraphSegments(text, options, target) {
+  const normalized = String(text ?? "");
+  const parts = normalized.split(/\r?\n/);
+  if (parts.length === 0) {
+    target.push({ text: "", options });
+    return;
+  }
+  for (const part of parts) {
+    target.push({ text: part, options });
+  }
+}
+
+function resolveParagraphStyle(entry, baseStyle) {
+  const opts = entry.options || {};
+  const fontFace =
+    (opts.fontFace && String(opts.fontFace).trim()) ||
+    baseStyle.fontFace ||
+    "Arial";
+  const fontStyle =
+    opts.italic === true || opts.fontStyle === "italic"
+      ? "italic"
+      : baseStyle.fontStyle || "normal";
+  const fontWeight =
+    opts.bold === true || String(opts.fontWeight || "").toLowerCase() === "bold"
+      ? "bold"
+      : baseStyle.fontWeight || "normal";
+  const fontSizePt =
+    toNumber(opts.fontSize, baseStyle.fontSizePt) || baseStyle.fontSizePt;
+  const leading =
+    toNumber(opts.leading, baseStyle.leading) || baseStyle.leading || 1.15;
+  const paraSpaceAfterPt =
+    toNumber(opts.paraSpaceAfter, baseStyle.paraSpaceAfterPt) ||
+    baseStyle.paraSpaceAfterPt ||
+    0;
+  const hasBullet = !!opts.bullet;
+  let indentPt = toNumber(opts.indent, NaN);
+  if (!Number.isFinite(indentPt) && hasBullet) {
+    indentPt = toNumber(opts.bullet.indent, NaN);
+  }
+  if (!Number.isFinite(indentPt)) indentPt = 0;
+  const hangingPt = toNumber(opts.hanging, 0) || 0;
+  let textIndentIn = 0;
+  if (indentPt > 0) {
+    if (hasBullet) {
+      // PowerPoint-style bullets: "indent" is the distance from the left edge
+      // of the text box to the start of the text (the bullet itself is hung
+      // using the hanging value). This means the available width for the text
+      // is boxWidth - indent, not boxWidth - (indent - hanging). Modeling it
+      // this way matches the manual line counts from PowerPoint/LibreOffice.
+      textIndentIn = indentPt / 72;
+    } else {
+      // Non-bullet paragraphs keep the prior behavior where hanging reduces
+      // the effective indent (similar to CSS text-indent).
+      textIndentIn = Math.max(0, (indentPt - hangingPt) / 72);
+    }
+  }
+  return {
+    text: entry.text || "",
+    fontFace,
+    fontStyle,
+    fontWeight,
+    fontSizePt,
+    leading,
+    paraSpaceAfterIn: paraSpaceAfterPt / 72,
+    textIndentIn,
+  };
+}
+
+function getFontData(face, fontStyle, fontWeight) {
+  const key = makeFontCacheKey(face, fontStyle, fontWeight);
+  if (fontKitCache.has(key)) return fontKitCache.get(key);
+  const fontPath = findFontPath(face, fontStyle, fontWeight);
+  if (!fontPath) {
+    fontKitCache.set(key, null);
+    return null;
+  }
+  try {
+    let font = fontkit.openSync(fontPath);
+    if (font && typeof font.fonts === "object") {
+      font = selectCollectionFont(font, fontStyle, fontWeight);
+    }
+    if (!font || typeof font.layout !== "function") {
+      fontKitCache.set(key, null);
+      return null;
+    }
+    registerCanvasFontVariant(fontPath, face, fontStyle, fontWeight, key);
+    const payload = { font, path: fontPath };
+    fontKitCache.set(key, payload);
+    return payload;
+  } catch (err) {
+    fontKitCache.set(key, null);
+    return null;
+  }
+}
+
+function makeFontCacheKey(face, fontStyle, fontWeight) {
+  const family = (face || "Arial").trim();
+  const style = (fontStyle || "normal").toLowerCase();
+  const weight = (fontWeight || "normal").toLowerCase();
+  return `${family}::${style}::${weight}`;
+}
+
+function registerCanvasFontVariant(
+  fontPath,
+  face,
+  fontStyle,
+  fontWeight,
+  cacheKey
+) {
+  if (registeredFontVariants.has(cacheKey)) return;
+  try {
+    Canvas.registerFont(fontPath, {
+      family: face,
+      style: fontStyle || "normal",
+      weight: fontWeight || "normal",
+    });
+    registeredFontVariants.add(cacheKey);
+  } catch (err) {
+    // ignore registration failure; measurement will fall back to Skia default
+  }
+}
+
+function findFontPath(face, fontStyle, fontWeight) {
+  const family = (face || "").trim();
+  if (family.length === 0) return null;
+  const key = makeFontCacheKey(family, fontStyle, fontWeight);
+  if (fontPathCache.has(key)) return fontPathCache.get(key);
+  const styleParts = [];
+  if ((fontWeight || "").toLowerCase() === "bold") styleParts.push("Bold");
+  if ((fontStyle || "").toLowerCase() === "italic") styleParts.push("Italic");
+  const styleQuery =
+    styleParts.length > 0 ? `:style=${styleParts.join(" ")}` : "";
+  const query = `${family}${styleQuery}`;
+  const result = spawnSync("fc-match", ["-f", "%{file}", query], {
+    encoding: "utf8",
+  });
+  if (result.status === 0) {
+    const output = String(result.stdout || "").trim();
+    if (output.length > 0) {
+      fontPathCache.set(key, output);
+      return output;
+    }
+  }
+  fontPathCache.set(key, null);
+  return null;
+}
+
+function selectCollectionFont(collection, fontStyle, fontWeight) {
+  const fonts = collection.fonts || [];
+  if (fonts.length === 0) return null;
+  const wantItalic = (fontStyle || "").toLowerCase() === "italic";
+  const wantBold = (fontWeight || "").toLowerCase() === "bold";
+  let best = fonts[0];
+  let bestScore = scoreFontVariant(best, wantItalic, wantBold);
+  for (let i = 1; i < fonts.length; i++) {
+    const candidate = fonts[i];
+    const score = scoreFontVariant(candidate, wantItalic, wantBold);
+    if (score > bestScore) {
+      best = candidate;
+      bestScore = score;
+    }
+  }
+  return best;
+}
+
+function scoreFontVariant(font, wantItalic, wantBold) {
+  if (!font) return -1;
+  const name = String(font.fullName || font.postscriptName || "").toLowerCase();
+  const isItalic = /italic|oblique/.test(name);
+  const isBold = /bold|black|heavy|semibold|extrabold/.test(name);
+  let score = 0;
+  if (isItalic === wantItalic) score += 1;
+  if (isBold === wantBold) score += 1;
+  return score;
+}
+
+// Empirical width scaling to better match PowerPoint/LibreOffice line breaks.
+// A tiny global shrink (about -1.5%) nudges borderline words to wrap the same
+// way Office does, with per-script tweaks for cases where our measurer
+// systematically under- or over-estimates glyph widths. We intentionally avoid
+// per-font calibration so this helper generalizes beyond the regression deck.
+function getWidthScaleForParagraph(paragraph) {
+  if (!paragraph || typeof paragraph.text !== "string") return 1;
+  const text = paragraph.text;
+  // Thai script: our measurer tends to slightly over-estimate, which can cause
+  // extra wraps. Give it a bit more room horizontally.
+  if (/[ก-๛]/u.test(text)) {
+    return 1.2;
+  }
+
+  // Arabic: we usually underestimate, so shrink available width a bit more to
+  // encourage earlier breaks.
+  if (/[\u0600-\u06FF]/u.test(text)) {
+    return 0.97;
+  }
+
+  // Base shrink for most Latin and other scripts.
+  return 0.985;
+}
+
+// Build options to pass directly to pptx.addText. We exclude measurement-only
+// fields and fill sensible defaults (e.g., fontSize) so callers can spread
+// the result into addText just like the image sizing helpers.
+function buildPassthroughOptions(opts, fontSizePt, margins) {
+  const exclude = new Set([
+    "text",
+    "lines",
+    "w", // will be set by calcTextBox
+    "h", // will be set by calcTextBox
+    // fontFace/style/weight are useful for addText; allow passthrough
+    "leading",
+    "padding",
+  ]);
+  const out = {};
+  for (const k of Object.keys(opts)) {
+    if (!exclude.has(k)) out[k] = opts[k];
+  }
+  if (out.fontSize == null) out.fontSize = fontSizePt;
+  if (opts.margin != null) out.margin = margins;
+  return out;
+}
+
+function getTextMeasurer() {
+  // Skia-canvas only for accurate shaping and Fontconfig-based resolution.
+  // Throws if skia-canvas is not available.
+  const canvas = new Canvas(2, 2);
+  const ctx = canvas.getContext("2d");
+  const PX_PER_IN = 96;
+  return (text, fontSizePt, fontFace, fontStyle, fontWeight) => {
+    const px = (fontSizePt / 72) * PX_PER_IN;
+    const style = fontStyle || "normal";
+    const weight = fontWeight || "normal";
+    // CSS shorthand: style weight size family
+    ctx.font = `${style} ${weight} ${px}px ${fontFace || "Arial"}`;
+    const metrics = ctx.measureText(text);
+    return (metrics.width || 0) / PX_PER_IN;
+  };
+}
+
+function normalizeMargins(m) {
+  const toInches = (value) =>
+    typeof value === "number" && Number.isFinite(value) ? value / 72 : 0;
+  if (m && typeof m === "object") {
+    if (Number.isFinite(m.left) || Number.isFinite(m.top)) {
+      return {
+        left: toInches(m.left),
+        right: toInches(m.right),
+        top: toInches(m.top),
+        bottom: toInches(m.bottom),
+      };
+    }
+  }
+  const all = toInches(m);
+  return { left: all, right: all, top: all, bottom: all };
+}
+
+function normalizeText(textOrRuns) {
+  if (Array.isArray(textOrRuns)) {
+    return textOrRuns
+      .map((item) => {
+        if (typeof item === "string") return item;
+        if (item && typeof item.text === "string") return item.text;
+        return "";
+      })
+      .join("");
+  }
+  return typeof textOrRuns === "string" ? textOrRuns : String(textOrRuns ?? "");
+}
+
+function toNumber(v, fallback) {
+  const n = typeof v === "string" ? parseFloat(v) : v;
+  return Number.isFinite(n) ? n : fallback;
+}
+
+module.exports = {
+  calcTextBoxHeightSimple,
+  calcTextBox,
+  autoFontSize,
+};