feat: Major grammar improvements and refactoring

- Refactor statement parsing with proper precedence handling
- Improve block structure parsing with indent/dedent support
- Enhance control flow parsing (conditionals, loops)
- Add print command support
- Improve function declaration parsing
- Update scanner for better string and comment handling
- Add comprehensive test corpus
- Better handling of newlines and statement boundaries

corpus/debug.txt

@@ -0,0 +1,13 @@
+Debug EOF
+=========
+?hp < 10
+  activate potion
+---
+(source_file
+  (conditional
+    (binary_expression (identifier) (number))
+    (block
+      (command (identifier) (identifier))
+    )
+  )
+)