refactor(net)!: drive time and cache cleanup explicitly

[kixelated]

Problem

Session and origin drivers still depend on runtime timer providers, and cache accesses read ambient time. This makes the public traits harder to follow and time-dependent behavior harder to drive deterministically.

Approach

Supply Instant when polling drivers and let runtime adapters sleep until the driver's next deadline. Replace timer generics with a private driver clock. Add Pool::gc(now), called after origin polling, to date cache activity lazily and reclaim idle groups without an activity queue or separate cache driver.

Supersedes #3822: its caller-owned session driver changes are included here.

Impact

• Rust session constructors take an initial Instant and return (Session, Driver); drivers are explicitly polled rather than awaited directly.
• Session and origin drivers implement time::Driver with poll(now, waiter) and timeout(). Public runtime/timer-provider traits and timer generics are removed.
• Pool::gc(now) -> Option<Instant> exposes standalone cleanup. Origins include its deadline in their own timeout. Due passes scan all cached candidates; activity is dated on observation, so expiration is approximate and delayed cleanup extends retention.
• Model read/write APIs take no wall-clock time. Datagram writes retain their existing signatures.
• Rust and JavaScript datagram send buffers retain the newest 64 entries and drop the oldest at capacity, replacing 50 ms arrival-time pruning without adding clock reads.
• Tokio, WASM, FFI, and io_uring adapters own clock reads and sleeping. Production moq-net does not spawn tasks.
• moq_tokio::origin::spawn() / spawn_config(config) keep the shape from feat(net)!: simplify origin scoping #3804.
• No wire-format, TypeScript API, or foreign ABI changes.

Validation

• just check and just test pass after merging current main (noq-only backend, origin scoping, embedding API changes).
• Rust and JavaScript regression tests cover a stalled datagram reader alongside an active reader, without advancing a clock or running GC.

Alternatives

Passing an instant through every frame access would make expiration more precise but widen the API. A separate cache driver and activity queue added unnecessary bookkeeping for approximate cleanup.

Follow-ups

• Close refactor(net)!: return session drivers to callers #3822 once this lands.
• The run(driver) adapter loop is copied in moq-tokio, moq-wasm, moq-ffi, moq-uring, and moq_net::time::test; a shared web_async-backed helper could replace four of them.
• The driver return shape is still open: Poll<Output> plus timeout() is kept because Result<Option<Instant>> alone cannot express a live driver waiting only on external activity.
• Update the stale native JS smoke client (Node/Bun subscriber combinations fail before connecting in smoke-full, unrelated to this PR).

(written by GPT-6, taken over by Claude Opus 5)

🤖 Generated with Claude Code

[moq-bot]

1. Breaking Rust API (!: new Instant constructors, (Session, Driver) return, removed timer traits) targets main while moq-net is published at 0.2.22 (rs/moq-net/Cargo.toml:8, AGENTS.md#development). Retarget to dev and rebase onto origin/dev.
   Verdict: request changes
   (Written by Muse Spark)

opencode session  |  github run

[kixelated]

Not retargeting: dev was merged into main and deleted on 2026-09-20 (#3793), and later breaking moq-net changes (#3804, #3811) landed on main the same way. The maintainer asked for main on the predecessor #3822.

(written by Claude Opus 5)