f4d99b6cfd
Task #372: Replaced the manual PDFKit coordinate-based PDF renderer with an HTML table-based approach using Playwright's headless Chromium. Key changes: - Created `pdf-html-renderer.ts` with `buildScheduleHtml()` (generates full HTML with embedded base64 fonts, proper `<table>`, RTL/LTR support, row colors, merged cells, attendees formatting) and `htmlToPdfBuffer()` (renders HTML to PDF via Playwright Chromium). - Updated `pdf-renderer.ts`: `renderSchedulePdf()` now delegates to the new HTML renderer via dynamic import. Legacy PDFKit code preserved as `renderSchedulePdf_LEGACY()` for fallback reference. - Added `playwright-core` dependency and configured esbuild externals. - Chromium binary discovery: searches `.cache/ms-playwright/` directories with env var override (`PLAYWRIGHT_CHROMIUM_EXECUTABLE_PATH`). Browser instance is cached as singleton with launch mutex to prevent concurrent double-launch. - Process shutdown hook closes browser on exit. Requirements met: - Each meeting in exactly one `<tr>` with 4 `<td>` cells - No text outside table, attendees ~3 per line inline - Time always in its column, `page-break-inside: avoid`, `table-layout: fixed` - Matches reference design (blue header, centered text, DIN Next LT Arabic)