Add modular renderer, PDF output, and session transcript

[houfu]

Summary

• PDF output for docx templates — after rendering a .docx, Codraft now attempts PDF conversion via docx2pdf (uses MS Word on macOS/Windows, LibreOffice on Linux) with a LibreOffice headless fallback. Soft-fails with a warning if neither tool is available; the .docx is always delivered.
• Modular, on-demand dependency installation — core packages (docxtpl, pyyaml, jinja2) are installed upfront; docx2pdf is installed only for docx jobs and weasyprint only for HTML jobs. No unnecessary packages loaded.
• Session transcript — after rendering, the Orchestrator generates transcript.md in the job folder recording the full interview: values collected, conditional sections included/skipped, and loop items. Works natively in Claude Code and Cowork (both render Markdown).
• Orchestrator updated — Phase 7 now generates the transcript (Step 7a) then presents results with links to all output files including the transcript (Step 7b).
• Output folder deduplication — renderer no longer silently overwrites an existing job folder; appends _2, _3, etc. when a same-named folder already exists.
• Docs updated — quick-rendering feature page, templates reference, introduction, and changelog (v0.2.1 entry added).
• Prominent Download button on docs landing page — hero now has a direct Download button linking to codraft-latest.zip, so Cowork users can download without navigating into the install guide.

Test plan

• Run codraft on templates/_examples/Bonterms_Mutual_NDA/ (simple docx) — confirm transcript.md has clean table-only sections, no conditional annotations
• Run codraft on templates/_examples/consulting_agreement/ (docx, groups + conditionals + loop) — confirm .docx + .pdf produced, transcript sections annotated correctly, loop items as **Item N** sub-sections
• Run codraft on templates/_examples/event_invitation/ (HTML, conditionals + loop) — confirm transcript saved to HTML job folder
• Render the same template twice in one day — confirm second job gets _2 suffix, first job untouched
• Soft-fail path: remove/rename soffice and uninstall docx2pdf — confirm .docx delivered with warning message
• No regression: both template types still render correctly
• Docs landing page: confirm four hero buttons render (Get Started, Download, Feature Tour, GitHub); Download triggers codraft-latest.zip download

🤖 Generated with Claude Code