Structs, arrays, owned strings, memory model, modules, debug info

- struct with default values; constructors Point(1, 2) / Point(x: 1); field access, auto-deref through pointers
- []T arrays with bounds checks, literals, for-each, push/pop/insert/remove/clear/resize/find/contains/join/slice/reverse/sort
- str carries its length: .len, s[i], +, comparison, sub/find/split/trim/upper/lower/replace/repeat/bytes, str(x), int(s), float(s)
- Memory: values own their memory and are freed at the end of their block; assignment copies, temporaries move;
  parameters are lent and only copied when the function changes them; defer; new()/free() for manual heap memory
- input(), read_file/write_file/file_exists, exit(), fn main([]str args)
- Finch modules: import name, module.fn(), module.Struct
- C structs from headers (fields, fixed arrays, nested); passed and returned by value with the System V x86-64 ABI;
  addr(fn) gives C a callback
- link "file.c" compiles and links your own C code
- -g emits DWARF debug info (gdb/lldb)
- Small C runtime (runtime/finch_rt.c) embedded in the compiler, cached in ~/.cache/finch
- Tests: 58, all clean under valgrind (MEMCHECK=1 tests/run.sh)

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

examples/guess.fn

@@ -0,0 +1,27 @@
+// Guess the number: input, loops and conversions.
+import "stdlib.h"
+import "time.h"
+
+fn main() {
+    srand(u32(time(null)))
+    secret := rand() % 100 + 1
+    tries := 0
+    print("I'm thinking of a number from 1 to 100.")
+    while true {
+        answer := input("Your guess: ")
+        if answer.len == 0 {
+            print("Bye!")
+            return
+        }
+        guess := int(answer)
+        tries += 1
+        if guess < secret {
+            print("Higher!")
+        } else if guess > secret {
+            print("Lower!")
+        } else {
+            print("Yes! It was", secret, "- you needed", tries, "tries.")
+            return
+        }
+    }
+}