Fix WebGL page cache and flip sequencing

scripts/check-webgl-book-runtime.js

@@ -27,6 +27,7 @@ async function main() {
         const minLabel = document.getElementById('webgl_book_nav_min_label');
         const maxLabel = document.getElementById('webgl_book_nav_max_label');
         const textureInfo = window.BookLabDebug.getTextureInfo();
+        const runtimeInvariants = window.BookLabDebug.getRuntimeInvariants?.() || {};
         const initialBookState = window.BookLabDebug.getBookState();
         const initialSliderMax = slider?.max || null;
         const initialMinLabel = minLabel?.textContent || '';
@@ -56,6 +57,12 @@ async function main() {
             spreadCount: 8,
             writtenPageLimit: 10
         });
+        const initialNavigationDisabled = {
+            topBackward: Boolean(document.getElementById('flip_backward')?.disabled),
+            topFastBackward: Boolean(document.getElementById('fast_flip_backward')?.disabled),
+            bottomStart: Boolean(document.getElementById('webgl_book_nav_start')?.disabled),
+            bottomBack: Boolean(document.getElementById('webgl_book_nav_back')?.disabled)
+        };
         slider.value = '100';
         slider.dispatchEvent(new Event('input', { bubbles: true }));
         await new Promise(resolve => {
@@ -158,9 +165,21 @@ async function main() {
                 new Promise(resolve => window.setTimeout(() => resolve(false), 5000))
             ]);
         const postTargetFlipState = window.BookLabDebug.getBookState();
+        window.BookLabDebug.setPaginationStateForTest({
+            spreadIndex: 5,
+            spreadCount: 8,
+            writtenPageLimit: 10
+        });
+        const endNavigationDisabled = {
+            topForward: Boolean(document.getElementById('flip_forward')?.disabled),
+            topFastForward: Boolean(document.getElementById('fast_flip_forward')?.disabled),
+            bottomForward: Boolean(document.getElementById('webgl_book_nav_forward')?.disabled),
+            bottomEnd: Boolean(document.getElementById('webgl_book_nav_end')?.disabled)
+        };
 
         return {
             navExists: Boolean(nav),
+            runtimeInvariants,
             initialSliderMax,
             initialMinLabel,
             initialMaxLabel,
@@ -176,6 +195,7 @@ async function main() {
                 height: cacheProbeResult?.height || 0
             },
             grownBookState,
+            initialNavigationDisabled,
             clampedSliderValue,
             percentReserveState,
             overlayLayout,
@@ -186,6 +206,7 @@ async function main() {
             targetFlipFinished,
             targetFlipEventDetail,
             postTargetFlipState,
+            endNavigationDisabled,
             textureInfo
         };
     });
@@ -202,6 +223,11 @@ async function main() {
     if (result.initialBookState?.pageCount !== 300) failures.push(`expected initial pageCount 300, got ${result.initialBookState?.pageCount}`);
     if (result.initialBookState?.pageReserve !== 50) failures.push(`expected initial pageReserve 50, got ${result.initialBookState?.pageReserve}`);
     if (result.initialBookState?.progress !== 0) failures.push(`expected initial progress 0, got ${result.initialBookState?.progress}`);
+    if (Math.abs(Number(result.runtimeInvariants?.targetFrameDurationMs || 0) - (1000 / 60)) > 0.001) {
+        failures.push(`expected 60fps target frame duration, got ${result.runtimeInvariants?.targetFrameDurationMs}`);
+    }
+    if (result.runtimeInvariants?.flipFrontBackShareMaterial) failures.push('flip front/back materials are shared instead of independently switchable');
+    if (!result.runtimeInvariants?.mirrorRefreshesEveryFrame) failures.push('mirror reflection is not marked for per-frame refresh');
     if (JSON.stringify(result.pageSpreadMap) !== JSON.stringify([[0, 0], [1, 1], [2, 2], [3, 2], [4, 3], [5, 3]])) {
         failures.push(`unexpected page-to-spread map ${JSON.stringify(result.pageSpreadMap)}`);
     }
@@ -213,6 +239,9 @@ async function main() {
         failures.push(`WebGL page cache probe failed: ${JSON.stringify(result.pageCacheProbe)}`);
     }
     if (result.grownBookState?.pageCount !== 310) failures.push(`expected page count to grow to 310 at writable limit, got ${result.grownBookState?.pageCount}`);
+    if (!result.initialNavigationDisabled?.topBackward || !result.initialNavigationDisabled?.topFastBackward || !result.initialNavigationDisabled?.bottomStart || !result.initialNavigationDisabled?.bottomBack) {
+        failures.push(`backward navigation should be disabled at first page: ${JSON.stringify(result.initialNavigationDisabled)}`);
+    }
     if (result.finalSliderMax !== '310') failures.push(`expected final slider max 310, got ${result.finalSliderMax}`);
     if (result.finalMaxLabel !== '310') failures.push(`expected final max label 310, got ${result.finalMaxLabel}`);
     if (result.clampedSliderValue !== '10') failures.push(`expected slider clamp to written page 10, got ${result.clampedSliderValue}`);
@@ -233,6 +262,9 @@ async function main() {
         eventDetail: result.targetFlipEventDetail
     })}`);
     if (result.postTargetFlipState?.spreadIndex !== 2) failures.push(`targeted page flip should commit spread 2, got ${result.postTargetFlipState?.spreadIndex}`);
+    if (!result.endNavigationDisabled?.topForward || !result.endNavigationDisabled?.topFastForward || !result.endNavigationDisabled?.bottomForward || !result.endNavigationDisabled?.bottomEnd) {
+        failures.push(`forward navigation should be disabled at written end: ${JSON.stringify(result.endNavigationDisabled)}`);
+    }
     if (!result.textureInfo?.debug?.left?.painted || !result.textureInfo?.debug?.right?.painted) failures.push('page texture publish did not paint both pages');
 
     if (failures.length) {