Add TOKEN_PIPEPIPE token for '||' syntax, implement or() parsing function with CODE_OR bytecode, and add VM interpreter logic that short-circuits on truthy left operand. Update .gitignore to exclude *.xccheckout files, extend test coverage for falsy behavior in and.wren and if.wren, and add comprehensive or.wren test suite verifying short-circuit semantics and truthiness rules.
Add TOKEN_AMPAMP token to the lexer for parsing '&&' operator, introduce PREC_LOGIC precedence level for proper expression parsing, implement the `and()` compiler function that emits CODE_AND with a patchable jump offset, and add runtime support in the VM with IS_FALSE macro for truthiness checking. Include comprehensive test cases in test/and.wren verifying short-circuit behavior and return values.
