Feature Parity — Development History

Stage 4 of the in-browser swactor runtime. Enables swactor-std extensions (naming, monitoring, groups) and core actor watching in the wasm crate.

Changes

Added wasm feature to crates/std/Cargo.toml (forwards to swactor/wasm)
Changed swactor dependency to default-features = false, forwarding getrandom feature when active (getrandom = ["dep:getrandom", "swactor/getrandom"])
Cfg-gated getrandom::getrandom() call in router.rs RoutingStrategy::Random — falls back to round-robin when getrandom feature is disabled (wasm mode)

Added register_name(name, addr) method to RuntimeNaming trait and impl — allows registering a name for an already-spawned actor from outside the runtime — complements existing spawn_named (which spawns + registers atomically)

Fixed gap in worker.rs tick_all: externally-stopped actors (via rt.stop_actor()) were not added to the deaths list, so core WatchRegistry (phase 5b) never fired for them. Added deaths.push((addr, ExitReason::Stopped)) when StopSignal is intercepted (line 737). All 140 existing native tests continue to pass.

WasmRuntime::new() now installs StdExtension automatically
New inbox type: WasmInboxString for receiving string notifications
Naming API: register_name, where_is, unregister_name, registered_names
Groups API: join_group, leave_group, publish_to_group_u32, group_member_count, group_names
Stats API: total_messages, total_panics (returned as f64 for JS compat)
New demo actors:
- Sentinel — watches a target via ctx.watch(), reports death to string inbox
- GroupMember — joins a group on start, forwards u32 messages to report inbox

#	Decision	Rationale
1	StdExtension always installed	Browser runtime should have full naming/groups by default
2	Stats as f64, not u64	wasm-bindgen maps u64 to BigInt which JSON.stringify rejects
3	Sentinel actor for watching	Demonstrates core watching from JS without exposing Watch API directly
4	register_name on RuntimeNaming	Needed for post-spawn registration from JS (no actor context available)
5	Round-robin fallback for Random routing	wasm mode disables getrandom; graceful degradation preferred

22 new assertions across 10 new test scenarios (30 total, from 10):

Test	Scenario
naming — register_name and where_is	Register name, resolve, verify not-found returns undefined
naming — unregister_name	Unregister returns previous addr, name no longer resolves
naming — registered_names	Lists all registered names as CSV
naming — duplicate name rejected	Second registration with same name fails
groups — join_group and publish_to_group_u32	Two members receive broadcast message
groups — leave_group	Member count decreases after leave
groups — group_names	Lists all active group names
watching — sentinel reports actor death	Stop target → sentinel receives death notification
stats — total_messages	Counts processed messages across workers
stats — total_panics starts at zero	Fresh runtime has zero panics