[xxxsen]

Summary

A progressing isolated-web content read currently expires after 15 seconds total. Pair the new runtime release with a Service Worker that renews the matching read only when its cumulative byte count advances.

 isolated resource read
+ READ_STARTED: start the active-read idle clock once
+ READ_PROGRESS: renew on increasing valid network bytes
+ renew queued reads while admission makes real progress

Pin the complete formal runtime v0.86.0 input set through the normal release-pin command. Its content policy uses 2 MiB network windows, prefetches the adjacent window after reading beyond halfway, and fetches files up to 5 MiB whole. Internal persistent blocks remain 256 KiB.

Evidence

• Before: a slow active read can fail at 15 seconds despite receiving data.
  After: the Service Worker regression completes a read spanning 32 seconds with advancing bytes; repeated start notifications, duplicate counters and another active read cannot prolong a stalled read.
• Local Web checks passed: structure/style rules, lint, types, 570 tests and the Next build.
• Runtime validation: 2,301 tests and 39 focused browser cases cover the new policy, real slow transfers through async/sync bridges, persistent-cache reuse and bounded prefetch/memory.
• All four core bridges have immutable releases with the matching Content I/O contract. PPSSPP additionally passed 58 native unit tests and 342 tests_good software-renderer cases.
• Formal v0.86.0 host and both Provider bundles were downloaded and verified through the standard preparation path. Actual MV, MZ and PSP Runs used the exact published module and bundle digests.
• Formal samples covered MV map startup and a warm title startup with no game-asset downloads, MZ files of 5,324,902 and 7,653,850 bytes split into 2 MiB ranges with clipped tails, and a PSP gameplay save restored in a different Run. Paused PSP canvas-region captures seven seconds apart were identical.
• All 11 Retrom PR checks passed, including backend, integration, contracts, Web, four browser viewports and the branch image build.

Merge Danger

Door: one-way once the production tag is published.

Blast Radius: content-loading

The shared policy applies to managed game reads, including MV/MZ/TyranoScript. Runtime bundles and core assets remain immutable; existing valid game-cache blocks keep their identities and layout.