docs: distinguish ready VM work from idle provider polling

src/README.md

@@ -164,7 +164,7 @@ UiBridge::begin_layout_frame/resume_layout_frame now expose PendingLayout around
 ReplSession now owns a resumable RefreshWork containing window traversal, pending bridge layout, unpublished per-window documents and the cumulative refresh work budget. poll_refresh advances one refresh stage or VM quantum; only a complete stable pass replaces the session's full document map. Synchronous callers drain the same state machine. Failure stops the domain, releases any pending bridge work and preserves the externally published picture. refreshYields counts cooperative refresh returns, not wall-clock time. Only still-pending Mount preparation is rolled back; completed callbacks remain committed.
 
 
-Viewport refresh now advances through ReplSession's saved refresh state on worker idle turns. A turn advances one traversal stage or a 256-instruction layout quantum; a pending job shortens the next worker wait to 1 ms. Tasks/window commands and document publication wait for complete refresh. ui.stats().refreshYields reports cooperative idle returns. Mutating requests wait across worker turns for the existing job, so they cannot run inside its read-only scope. Mutating requests are serialized; newer viewport targets coalesce by cancelling unpublished layout. Initial source execution remains atomic; its layout can park across worker turns. Explicit REPL/event refresh can park across worker turns. Idle tasks deliver at most one callback per turn and park subsequent layout; callbacks and individual native nodes remain atomic. Large intrinsic trees use the sliced driver; small intrinsic trees keep the fast path.
+Viewport refresh now advances through ReplSession's saved refresh state on worker idle turns. A turn advances one traversal stage or a 256-instruction layout quantum; ready layout/paint or coroutine work checks the request queue without a timed wait and yields to other ready OS threads between turns. An accepted pending input/candidate also yields without adding a fixed millisecond delay per VM quantum; control, epoch and viewport checks still run on every turn. When only external completion/timers are pending, the normal idle wait remains 100 ms. Tasks/window commands and document publication wait for complete refresh. ui.stats().refreshYields reports cooperative idle returns. Mutating requests wait across worker turns for the existing job, so they cannot run inside its read-only scope. Mutating requests are serialized; newer viewport targets coalesce by cancelling unpublished layout. Initial source execution remains atomic; its layout can park across worker turns. Explicit REPL/event refresh can park across worker turns. Idle tasks deliver at most one callback per turn and park subsequent layout; callbacks and individual native nodes remain atomic. Large intrinsic trees use the sliced driver; small intrinsic trees keep the fast path.
 
 
 Runtime mutation entry points reject direct calls while refresh work is pending, before executing source or changing metadata; task polling defers. The API worker drains the saved refresh before accepting those mutations, keeping the runtime usable. Incremental refresh keeps the prior complete document map until a stable pass, including across window traversal boundaries where no VM read-only frame is currently active.
@@ -224,7 +224,7 @@ ui.spawn(owner,key,function) creates an owner-scoped cooperative Task for a zero
 
 Inside a function run by ui.spawn, `value = await task` waits for any timer/file/network/spawn Task and resumes at the same expression with its retained result. A source function may return a Number, String, managed Object or Unit; normal source annotations still apply. Task.result() and await share the result. `ui.sleep(owner,key,milliseconds)` creates a callback-free timer Task returning Unit. Plain calls/REPL can await an already completed Task; a pending await requires a coroutine and fails explicitly rather than blocking. There is no new async function declaration: ui.spawn explicitly schedules an ordinary Endor function. See examples/await-file.endor.
 
-A waiting coroutine retains its evaluated operand and frames as managed edges; waiting performs no VM execution or active 1ms spin. Source side effects and IO initiation before await are not replayed. When the dependency completes, the owning VM worker resumes the waiter through the existing fair quantum scheduler. Cancelling/replacing/closing the waiter releases its frames and operand; it does not automatically cancel an independently owned or shared dependency. Dependency cancellation propagates cancellation to its waiters without running the remainder. An unhandled dependency failure becomes a source await error (with the original provider message), fails the waiter and follows the existing shared-runtime fault rule; provider failure alone still only fails its own Task. Self-await and cyclic Task waits fail explicitly. Read-only layout/paint cannot await. Waiting state is reported as running, while active() remains true; result() is unavailable until completion. These APIs do not introduce try/finally or change the existing exception model.
+A waiting coroutine retains its evaluated operand and frames as managed edges; waiting performs no VM execution or active polling. Source side effects and IO initiation before await are not replayed. When the dependency completes, the owning VM worker resumes the waiter through the existing fair quantum scheduler. Cancelling/replacing/closing the waiter releases its frames and operand; it does not automatically cancel an independently owned or shared dependency. Dependency cancellation propagates cancellation to its waiters without running the remainder. An unhandled dependency failure becomes a source await error (with the original provider message), fails the waiter and follows the existing shared-runtime fault rule; provider failure alone still only fails its own Task. Self-await and cyclic Task waits fail explicitly. Read-only layout/paint cannot await. Waiting state is reported as running, while active() remains true; result() is unavailable until completion. These APIs do not introduce try/finally or change the existing exception model.
 
 
 While a native tab drag is held over an overflow arrow area, the strip waits 350ms then reveals one hidden tab every 120ms, including in a compatible destination window. The preview scroll does not activate Pages or change business state. Drawing, hit testing and insertion gaps share the same transient visible range; release uses its full-order insertion index. Leaving the strip stops the timer; release, Escape, a new press or runtime generation change restores the normal active-tab-centered strip. A resize or changing tab count clamps the range. Native drag/mixed-DPI behavior still requires platform validation; application-exit cleanup is described below.