[10] Port the ESC/POS parser and PDF ticket renderer

[jvwaldrich0]

Task 10 of 16 — these are sequential, do them in order.

Previous: #12 · Next: #14

Port target: cloudpark-toolkit (Go) → this repo (Rust). Reference paths below are relative to that repo.

Goal

Port the ESC/POS parser and the PDF ticket renderer. Tasks 12 and 13 both save tickets through it.

Scope

• Parse the ESC/POS stream a VKP80III receives: text + codepage, alignment, font size/emphasis, line feeds, barcodes, QR codes, raster/bit-image blocks, cut.
• Render the parsed ticket to a PDF page sized like the 80 mm roll and write it to the ticket dir with a timestamped filename.
• Public API: printer::render_ticket(bytes: &[u8], ticket_dir: &Path) -> Result<PathBuf>.
• Crates: printpdf (PDF) + image (raster blocks).

Reference

cloudpark-toolkit/internal/tcp105/printer/escpos.go (775 lines), printer.go, printer_test.go

Done when

• A captured real ticket byte stream renders to a PDF with readable text and the barcode/QR present.
• Unknown/unsupported ESC/POS sequences are skipped with a log line, never fatal.
• Unit test over a small fixture stream.