re: Size_Y is genuinely defaulted, and the loader leaves it at 0.0

pool_window.rs shows the Destroyer's raw tokens: "200.0" "Size_X" "Size_Y"
"2000.0" "Size_Z" -- Size_Y is a bare key, so the 13 runtime values recovered
earlier are real defaults, not a reader artefact.

The filler reads each size field through sub_822FC5A8, which loads f31 from
0x8209fd28 = 0.0 at entry and returns it on a pool miss, then stores to +52.
Nothing else in the 15876-byte filler writes +52, so the definition leaves a
defaulted Size_Y at 0.0 and the runtime 200 is written later.

Two corrections: the +48/+52/+56 comparison block builds a size-class bitmask
against 1000.0 (constant 0x8209fd20), not a has-value mask; and both earlier
Size_Y derivation candidates are refuted (one is a conditional pick, the other
multiplies into a different struct).

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

crates/sylpheed-formats/examples/pool_window.rs

@@ -0,0 +1,29 @@
+//! Raw token sequence around a key, for one record — the ground truth for
+//! "is this field actually defaulted, or is our reader missing it?"
+//! Run: pool_window <disc-root> <ID substring> <key>
+use sylpheed_formats::idxd::IdxdObject;
+use sylpheed_formats::pak::PakArchive;
+fn main() {
+    let disc = std::env::args().nth(1).unwrap();
+    let want = std::env::args().nth(2).unwrap();
+    let key = std::env::args().nth(3).unwrap();
+    let pak = PakArchive::open(format!("{disc}/dat/GP_MAIN_GAME_E.pak")).unwrap();
+    for e in pak.entries() {
+        let Ok(b) = pak.read(e) else { continue };
+        let Ok(o) = IdxdObject::parse(&b) else { continue };
+        let Some(id) = o.get_raw("ID") else { continue };
+        if !id.contains(&want) { continue; }
+        let t = o.tokens();
+        println!("=== {id}   get_f32({key}) = {:?}", o.get_f32(&key));
+        for (i, tok) in t.iter().enumerate() {
+            if tok == &key {
+                let lo = i.saturating_sub(6);
+                let hi = (i + 7).min(t.len());
+                for j in lo..hi {
+                    println!("   [{j}]{} {:?}", if j == i { " <-- key" } else { "        " }, t[j]);
+                }
+                println!();
+            }
+        }
+    }
+}