re: the break-composite alarm is false -- the container stores 3-6 copies of each buffer

locate_draw counts copies of a captured buffer. The f105 parts _rou_f105_break
claims exist 3-6 times over (the 2336-vert one: 6 direct AND 6 mirrored), and
every live LOD checked is anchored on a direct, byte-identical copy -- so the
composite taking the drawn copy costs nothing. This also calibrates the oracle:
'exact' (anchored at the drawn offset) is stricter than correct, so 45/46 is a
lower bound. Open: a resource landing on a MIRRORED copy would be a real defect
invisible to every count-based metric.

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

crates/sylpheed-formats/examples/locate_draw.rs

@@ -0,0 +1,53 @@
+//! How many copies of a captured buffer does a container hold?
+//!
+//! The twins showed that two resources decoding to one buffer can mean the
+//! container really holds two (mirrored) copies and our scan found only one.
+//! This asks that question for any draw: give it a `vbase`, and it reports every
+//! offset whose leading vertices match the draw's dumped positions — directly, and
+//! X-mirrored.
+//!
+//! Usage: locate_draw <container.xpr> <capture.log> <vbase-hex>...
+use sylpheed_formats::ship_capture::{parse_capture, parse_drawlog};
+
+fn main() {
+    let a: Vec<String> = std::env::args().collect();
+    let bytes = std::fs::read(&a[1]).expect("container");
+    let text = std::fs::read_to_string(&a[2]).expect("log");
+    let mut draws = parse_capture(&text);
+    if draws.is_empty() {
+        draws = parse_drawlog(&text);
+    }
+    let be = |at: usize| f32::from_be_bytes(bytes[at..at + 4].try_into().unwrap());
+
+    for want in &a[3..] {
+        let vb = u32::from_str_radix(want.trim_start_matches("0x"), 16).expect("hex vbase");
+        let Some(d) = draws.iter().find(|d| d.vbase == vb) else {
+            println!("vbase 0x{vb:08X}: not in this log");
+            continue;
+        };
+        let n = d.pos.len().min(8);
+        let mut direct = Vec::new();
+        let mut mirror = Vec::new();
+        for o in (0..bytes.len().saturating_sub(12 + 64 * 24)).step_by(4) {
+            for (flip, out) in [(1.0f32, &mut direct), (-1.0f32, &mut mirror)] {
+                let hit = (0..n).all(|k| {
+                    let at = o + k * 24;
+                    (be(at) - flip * d.pos[k][0]).abs() <= 1e-4
+                        && (be(at + 4) - d.pos[k][1]).abs() <= 1e-4
+                        && (be(at + 8) - d.pos[k][2]).abs() <= 1e-4
+                });
+                if hit {
+                    out.push(o);
+                }
+            }
+        }
+        println!(
+            "vbase 0x{vb:08X} vcount={}: {} direct copy/copies {:x?}, {} mirrored {:x?}",
+            d.vcount,
+            direct.len(),
+            &direct[..],
+            mirror.len(),
+            &mirror[..]
+        );
+    }
+}