Properties to JSONConvert Java .properties files to structured JSON with nested key support.

The parser processes the properties file line by line. Lines starting with # or ! are treated as comments and skipped. Empty lines are ignored. Key-value separation supports both = and : delimiters. The parser finds the first occurrence of either delimiter and splits the line there. Both key and value are trimmed of whitespace. Dotted key expansion: keys containing periods (e.g., db.connection.host) are split and create nested JSON objects. The parser walks the key parts, creating intermediate objects as needed, and sets the value at the deepest level. Escape sequences are processed: \n becomes newline, \t becomes tab, \\ becomes backslash. This matches Java's Properties file escape handling.