Compact PDF table layout to match reference design (Task #359)

Changes to artifacts/api-server/src/lib/pdf-renderer.ts:

- Reduced cellPadX from 6 to 4 (horizontal cell padding)
- Reduced cellPadY from 3 to 2 (vertical cell padding)
- Tightened lineHeight multiplier from 1.25 to 1.2
- Removed +2 padding buffer from heightOfString measurement loop
- Removed +2 from drawWrappingLine return value
- Tightened drawMixedLine return value (1.25→1.2)
- Consolidated header spacing from two moveDown(0.2+0.4) to one moveDown(0.3)
- Tightened title Y offset multiplier from 1.25 to 1.2
- Fixed row height probe to detect script per-line (matching draw path)
  instead of per-cell, preventing measurement/draw mismatch in
  mixed Arabic/Latin content now that the +2 cushion is removed

Result: Table rows are compact with no visible gaps between them,
matching the user's reference PDF (attached_assets/rrr1_1777879598338.pdf).
Row colors, cell borders, and footer positioning are unchanged.
Both AR and EN PDFs generate successfully (200 status).

artifacts/api-server/src/lib/pdf-renderer.ts

@@ -529,7 +529,7 @@ function drawMixedLine(
     });
     cursorX += r.width;
   }
-  return opts.fontSize * 1.25;
+  return opts.fontSize * 1.2;
 }
 
 function drawWrappingLine(
@@ -561,7 +561,7 @@ function drawWrappingLine(
     lineGap: -1,
     ...(features ? { features } : {}),
   });
-  return Math.max(opts.fontSize * 1.25, doc.y - before + 2);
+  return Math.max(opts.fontSize * 1.2, doc.y - before);
 }
 
 export async function renderSchedulePdf(input: RenderPdfInput): Promise<Buffer> {
@@ -639,9 +639,8 @@ export async function renderSchedulePdf(input: RenderPdfInput): Promise<Buffer>
     baseDirection: baseDir,
     mapping,
   });
-  doc.y = headerTopY + Math.max(titleSize * 1.25, input.logo ? logoBoxSize : 0);
-  doc.moveDown(0.2);
-  doc.moveDown(0.4);
+  doc.y = headerTopY + Math.max(titleSize * 1.2, input.logo ? logoBoxSize : 0);
+  doc.moveDown(0.3);
 
   if (input.meetings.length === 0) {
     drawMixedLine(doc, input.labels.none, {
@@ -728,11 +727,9 @@ export async function renderSchedulePdf(input: RenderPdfInput): Promise<Buffer>
     : [input.labels.no, input.labels.meeting, input.labels.attendees, input.labels.time];
   const headerWidths = isRtl ? [...colWidths].reverse() : colWidths;
 
-  const cellPadX = 6;
-  // Tightened from 5→3 to keep the table compact (we aim to fit a typical
-  // day on one page, mirroring the user's reference layout).
-  const cellPadY = 3;
-  const lineHeight = input.font.fontSize * 1.25;
+  const cellPadX = 4;
+  const cellPadY = 2;
+  const lineHeight = input.font.fontSize * 1.2;
 
   function drawHeader(): number {
     const headerHeight = lineHeight + cellPadY * 2;
@@ -840,32 +837,25 @@ export async function renderSchedulePdf(input: RenderPdfInput): Promise<Buffer>
       // sooner than a simple division would, causing rows to overlap.
       const lines = c.text.split("\n");
       let h = 0;
-      const arabicChars = [...c.text].filter(isArabicChar).length;
-      const dominantArabic = arabicChars * 2 > c.text.length;
-      const fk = fontKeyFor(dominantArabic, input.font.fontWeight, mapping);
-      const features = featuresFor(dominantArabic);
-      doc.font(fk).fontSize(input.font.fontSize);
-      const measureOpts: PDFKit.Mixins.TextOptions = {
-        width: widths[i] - cellPadX * 2,
-        align: c.align,
-        lineBreak: true,
-        // Mirror drawWrappingLine's lineGap so the probe matches the draw.
-        lineGap: -1,
-        ...(features ? { features } : {}),
-      };
+      const cellW = widths[i] - cellPadX * 2;
       for (const line of lines) {
         if (!line) {
           h += lineHeight;
           continue;
         }
-        // heightOfString returns pdfkit's exact rendered height for the
-        // wrapped paragraph (including its internal line gaps). Use it
-        // directly — rounding up to whole lineHeight units inflates rows
-        // by half a line and leaves visible empty space below cells.
-        // The +2 mirrors drawWrappingLine's per-line padding fallback so
-        // multi-line cells never get under-reserved.
-        const measured = doc.heightOfString(line, measureOpts);
-        h += Math.max(lineHeight, measured) + 2;
+        const lineArabicChars = [...line].filter(isArabicChar).length;
+        const lineDominantArabic = lineArabicChars * 2 > line.length;
+        const lineFk = fontKeyFor(lineDominantArabic, input.font.fontWeight, mapping);
+        const lineFeatures = featuresFor(lineDominantArabic);
+        doc.font(lineFk).fontSize(input.font.fontSize);
+        const measured = doc.heightOfString(line, {
+          width: cellW,
+          align: c.align,
+          lineBreak: true,
+          lineGap: -1,
+          ...(lineFeatures ? { features: lineFeatures } : {}),
+        });
+        h += Math.max(lineHeight, measured);
       }
       const finalH = h + cellPadY * 2;
       cellHeights.push(finalH);