docs: looking closer at the frame-rate word weakened it, and that is the result

The 16.16 reading of +0x04 rested on twelve bundles at 30.0. They are not twelve
witnesses: they are TWO bundles - pghud_range_main_em/emeff and
pghud_range_nose_em/emeff, both dur 30 - repeated across six language PAKs. A
30-frame flash is equally consistent with 0.5 s at 60 and 1 s at 30, so the
observation that "30.0 bundles are shorter" says almost nothing.

Worse for the clean fixed-point reading: the four bundles at 0x3C0001 would be
60.0000152 fps, which nobody authors. They are py_ranking_jump/py_ranking_next
dialogs, all dur 60. So the better reading is <rate:16>.<flag:16> - a rate-like
number in the high half and a small low field that is 0 on 2843 bundles and 1 on
four, meaning unknown.

Also stated: nothing in this container can settle it by timing, because the
emulator runs on software Vulkan far from real time - a stopwatch would measure
lavapipe rather than the game.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PMRJjbxLqZtsb5Vb7KunPE

crates/sylpheed-formats/tests/ui_header_time_disc.rs

@@ -69,6 +69,10 @@ fn header_0x08_against_the_keyframe_times() {
     let mut ratio: HashMap<u32, usize> = HashMap::new();
     // Does the rate word co-vary with anything?
     let mut by_rate: HashMap<u32, (usize, u32)> = HashMap::new(); // rate -> (bundles, max seen 0x08)
+    // The 16.16 frame-rate reading rests on twelve bundles at 30.0. If those are
+    // VARIANTS of 60.0 bundles - same elements, different rate - the reading
+    // gains a real discriminator; if they are unrelated one-offs it does not.
+    let mut odd_rate: Vec<String> = Vec::new();
 
     for_each_build(&root, |pak, bytes| {
         if bytes.len() < 0x20 {
@@ -86,6 +90,14 @@ fn header_0x08_against_the_keyframe_times() {
         e.0 += 1;
         e.1 = e.1.max(dur);
 
+        if rate != 0x3C_0000 && odd_rate.len() < 20 {
+            let names: Vec<&str> = build.elements.iter().map(|e| e.name.as_str()).take(6).collect();
+            odd_rate.push(format!(
+                "{pak}: rate {rate:#x} dur {dur} elements {} {:?}",
+                build.elements.len(),
+                names
+            ));
+        }
         let max_time = build
             .elements
             .iter()
@@ -124,6 +136,9 @@ fn header_0x08_against_the_keyframe_times() {
     for w in &worst {
         eprintln!("  over: {w}");
     }
+    for o in &odd_rate {
+        eprintln!("  non-60 rate: {o}");
+    }
 
     assert!(animated > 0, "no animated bundles — the sweep is broken");