feat(kio): add runtime-free timers

[kixelated]

Summary

• add a runtime-free native kio::time driver with sleep, interval, instant, reset, and deterministic test clocks
• retain Tokio idle-aware auto-advance under the test-only test-util feature while keeping normal kio builds free of Tokio
• migrate moq-net timer and instant call sites so Driver can be polled on any executor
• update paused-time tests and native/wasm documentation

The remaining native runtime dependency came from web_async::time, which maps timers to Tokio and panics when polled without a Tokio runtime. The new kio timer thread owns deadline scheduling and wakes kio waiters directly.

Public API changes

• adds native kio::time::{Instant, Sleep, Interval, sleep, sleep_until, interval}
• adds test-only kio::time::{pause, advance} behind test-util
• removes the kio::tokio module and its tokio feature
• no moq-net public or wire API changes; JS and protocol draft sync are not applicable

Test plan

• just fix
• just rs check
• cargo test -p kio (22 passed)
• cargo test -p moq-net (495 passed plus doctests)
• just test smoke
• plain local wasm check remains blocked by the repository's known getrandom/wasm_js configuration; CI owns the authoritative wasm build

(Written by GPT-5)

[sourcery-ai]

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