Set up development environment (AGENTS.md + startup deps)

[ebyron357]

Summary

Sets up the development environment for ALT-Label-System and documents it for future cloud agents. No application code is modified.

• Adds AGENTS.md with a ## Cursor Cloud specific instructions section covering repo layout (code lives on feature branches; main is README-only), Python/deps, the optional Ghostscript dependency, and how to run/build/validate.
• Configures a minimal, guarded startup update script: if [ -f requirements.txt ]; then python3 -m pip install -r requirements.txt; fi (safe on the empty main branch, idempotent, installs to user site).

Environment verified

Validated against the most complete feature branch (cursor/manufacturing-readiness-971b) via a worktree, since main has no code.

• ✅ pip install -r requirements.txt — reportlab, PyYAML, jsonschema, qrcode, Pillow installed cleanly
• ✅ python3 scripts/export_production.py — generated 8 can-label PDFs
• ✅ python3 scripts/export_syrup_production.py — generated 4 syrup-label PDFs
• ✅ python3 scripts/validate_spec.py — Score 51/51, retail readiness 10.0/10
• ✅ python3 scripts/validate_syrup_spec.py — Score 25/25
• ✅ python3 -m compileall -q src scripts — syntax check passed (no linter configured in repo)

Sample rendered output

Reserve 100mg Lychee can label
Original syrup label

_{To show artifacts inline, enable in settings.}