Brace-free surface

Romit source must not use braces, brackets, or parentheses in the surface syntax. If the lexer sees (, ), [, ], {, }, or a stray :, it reports P013:

Romit has no braces. Use indentation instead.

Allowed non-word symbols in code are limited to:

• Operators + - * / < > and == / != (or words such as is, is not, above, below)
• String quotes "
• Hex colours #RRGGBB
• Comments // or note

Calls use space-separated words, for example emit Greet with message "Hi" or set answer to 3 times 4 plus 2.

Types and collections use words instead of punctuation: List of Number, items at 0, go to /signup.