Finch 2.4.0: methods, maps, errors as values; str() of any value; macOS and ARM64 docs; Kate support

- fn Struct.method(...) with self by reference, also on C structs
- map[K]V: insertion-ordered hash maps, literals, m[k] += 1, has/get/remove/keys/values
- -> T! / -> !, return error(...), or <value>, or { err }, try; fallible int/float/read_file/write_file/delete_file
- for i, x in list / for k, v in map
- print and str() share one text formatter
- LSP: method and map completion, method signatures; grammar and snippets for VS Code and Kate
- tests: 74 (methods, errors, maps + 11 failure cases); docs at all three levels, en and pl

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/lexer.cpp

@@ -10,7 +10,7 @@ static const std::unordered_map<std::string, Tok> keywords = {
     {"in", Tok::In},       {"break", Tok::Break},   {"continue", Tok::Continue},
     {"true", Tok::True},   {"false", Tok::False},   {"null", Tok::Null},
     {"import", Tok::Import}, {"link", Tok::Link},   {"struct", Tok::Struct},
-    {"defer", Tok::Defer},
+    {"defer", Tok::Defer},  {"or", Tok::OrElse},     {"try", Tok::Try},
 };
 
 std::vector<Token> lex(int file) {
@@ -169,6 +169,8 @@ const char *tokName(Tok t) {
     case Tok::Link: return "'link'";
     case Tok::Struct: return "'struct'";
     case Tok::Defer: return "'defer'";
+    case Tok::OrElse: return "'or'";
+    case Tok::Try: return "'try'";
     case Tok::Colon: return "':'";
     case Tok::LParen: return "'('";
     case Tok::RParen: return "')'";