Task #586: Unify PDF column font & row shading

Two small fixes in artifacts/api-server/src/lib/pdf-html-renderer.ts:

1. Removed `font-weight: bold` from `.num-cell` so the # column inherits
   the body font weight (same as meeting/attendees/time columns). The
   header (`thead th`) keeps its bold styling unchanged.

2. Changed attendees and time cells in `buildMeetingRow` to use
   `coloredStyle` (was empty string ""), so when a row has a `rowColor`,
   the tint covers the whole row instead of only the # and meeting
   cells. The `numDarkStyle` (dark bg + white digit for variants with
   a border color) is preserved.

On-screen schedule, merged-cell rows, and cancelled-row red border
behavior are unchanged. API server restarted clean.

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

@@ -249,8 +249,8 @@ function buildMeetingRow(meeting: PdfMeeting, input: RenderPdfInput): string {
   const cellsLtr: TableCell[] = [
     { html: esc(String(meeting.dailyNumber)), cls: "num-cell", style: numDarkStyle },
     { html: titleHtml + location, cls: "meeting-cell", style: coloredStyle },
-    { html: attendeesHtml, cls: "attendees-cell", style: "" },
-    { html: `<span dir="ltr">${esc(time)}</span>`, cls: "time-cell", style: "" },
+    { html: attendeesHtml, cls: "attendees-cell", style: coloredStyle },
+    { html: `<span dir="ltr">${esc(time)}</span>`, cls: "time-cell", style: coloredStyle },
   ];
 
   const renderCells = (cells: TableCell[], allColored: boolean): string =>
@@ -428,7 +428,6 @@ tr {
 .num-cell {
   text-align: center;
   vertical-align: middle;
-  font-weight: bold;
 }
 
 .meeting-cell {