fix(docs): use production sandbox font paths - #171

Why

Production research PDF generation failed after successful report synthesis because the renderer looked for Liberation fonts in /usr/share/fonts/truetype/liberation2, while the Daytona production image provides them under /usr/share/fonts/truetype/liberation.

What changed

• Point the Markdown-to-PDF renderer at the Liberation Sans and Liberation Mono paths present in the production sandbox.
• Keep the report pipeline unchanged: the canonical Markdown shown in chat is still the exact input rendered to PDF.

Verification

• pnpm lint
• pnpm typecheck
• pnpm turbo build --force
• pnpm deadcode
• pnpm architecture:check
• pnpm turbo skills:build
• Reproduced the original ENOENT against the live Daytona sandbox.
• Ran the corrected renderer in that sandbox with headings, links, a four-column table, a task list, a blockquote, and sources; it exited successfully and emitted a valid PDF artifact.

No database migration, environment variable, vendor, or deployment-topology changes.