pre-alpha 5 (f65640a 2026-07-19)

• f65640ab npmignore: rm
• b8ddba6d codegen: cleanup debug
• 3b628529 codegen: simplify tmp by rming TMP_TAG
• c934cf51 various: rewrite bigint parse/codegen
• 7a2ad05b parse/codegen: remove code unneeded for own parser
• edbaa7fd runtime: don't host error if binary errors
• 3bcd6370 codegen: extract ts union types better
• 60452b19 codegen: parse string type as string|bytestring
• 832d335e render: always on and simplified good throw msgs