v0.86.3

Fixed

• The firehose cap now bounds what the wire carries. MAX_DATA_SIZE was measured against the caller's $data, but n, k and ts are stamped on afterwards, so a payload that cleared the cap on its own still shipped an oversized entry — 3895 bytes against a 3840 cap in the regression test. message() builds the entry first and fits THAT, and the last-resort floor keeps n, k and ts so a reader can still place the line.
• Every failed Ask showed "An error occurred" instead of why. useAsk reports a reason STRING — the substrate types a reply's error as ?string, and errorMessage() coerces every TM_ERROR payload before onDone sees it — but the page's handler read err.message, which is undefined on a string, so the real reason was discarded on both failure paths. The tests passed because they drove the handler with an Error object production never sends; they now use the string the runtime actually delivers, and fail against the old code.

Documentation

• The seven documents verified against source, then completed from it. Two passes held every existing claim to the code, the second re-deriving each rather than reviewing the first's reasoning. Every file:line citation became a symbol reference, because a cited line is right only until someone edits above it. Then all 931 non-test PHP and JS files across the six plugins were read to establish what these documents omit, and each resulting finding was verified against source again before being written — a claim that the Current-Request overlay passes Admin::devtools_overlay_pages() as its page value was dropped, since Current_Request_Overlay::enqueue_on_overlay_pages() never calls enqueue_react_page at all — it gates on its own is_overlay_page() and hand-rolls wp_enqueue_script.
• Every PHP and JS source file's documentation reviewed against its code. One agent per file, tests excluded: missing docblocks written, @param/@return drift corrected against the real signature, documentation for deleted behaviour removed, and the why recorded where the what was already plain. Comments describing history rather than the present are gone.
• JSDoc types repaired where the sweep's prose broke the type gate. An @type naming LazyExoticComponent with no type argument overrode correct inference and erased PerformanceDashboard's whole props contract; @ inside prose (@<priority>, @0) parses as a tag and is a syntax error; a %s was handed a number.