fix: C backend, parser, sema, HIR lowering for all examples

- C backend: strip c8/c16/c32 string prefixes in emitted C
- C backend: resolve imports to fully-qualified names (Std_Io_PrintLine)
- Parser: fix infinite loop on < in comparisons vs generic calls
- Parser: fix enum patterns without parens (Option::None)
- Parser: fix match expressions inside blocks
- Sema: extract pattern bindings for match arms
- HIR: lower match expressions to if-else chains with enum tag checks
- HIR/C backend: support block expressions as function return values
- Makefile: add integration tests for all 9 examples
- Add pattern_matching.bux example

.gitignore

@@ -1,13 +1,23 @@
 # Compiled binary
 buxc
+src/main
 
 # Nim cache
 nimcache/
 
 # Test binaries
 tests/lexer_test
+tests/parser_test
+tests/sema_test
+tests/hir_test
+tests/test_generics_parse
 tests/*.exe
 
 # Build artifacts
 build/
 *.o
+
+# Temporary directories
+_test_tmp_pkg/
+test_pkg/
+examples_pkg/