feat(async): add task::kill() for force-terminating async tasks

.agents/skills/awkernel-async-scheduler-testing/SKILL.md

@@ -0,0 +1,81 @@
+---
+name: awkernel-async-scheduler-testing
+description: Use when testing or debugging Awkernel async/await task scheduler behavior, including task kill, preemption, sleep/wake, timer interactions, QEMU reproduction, and SPIN model checking under specification/awkernel_async_lib/src/task/preemptive_spin.
+---
+
+# Awkernel Async Scheduler Testing
+
+Use this skill when changing or reviewing `awkernel_async_lib` task scheduling behavior: `kill()`, preemption, sleep/wake, timer wakeups, task registry removal, or scheduler queues.
+
+## Core workflow
+
+1. Identify whether the issue is in runtime code, model code, or a test app.
+2. Prefer `make` for kernel builds; do not replace kernel validation with direct `cargo` commands.
+3. Reproduce on the smallest layer first, then escalate:
+   - Rust/library check for compile-level regressions.
+   - SPIN for scheduler state-machine properties.
+   - RELEASE QEMU for real kernel behavior and shell responsiveness.
+4. Treat shell stuck as a scheduler/timer symptom, not necessarily a shell bug.
+
+## Build and QEMU commands
+
+Use RELEASE builds for QEMU experiments:
+
+```sh
+make x86_64 RELEASE=1
+make qemu-x86_64_nographic RELEASE=1
+```
+
+For kill-specific QEMU testing:
+
+```sh
+make x86_64 RELEASE=1 OPT='--release --features test_task_kill'
+make qemu-x86_64_nographic RELEASE=1
+```
+
+After feature tests complete, verify the shell still responds with a small expression such as `(+ 7 8)`. Intentional panic logs from panic-specific tests are not automatically failures; check the PASS/FAIL lines after the panic.
+
+## SPIN model checking
+
+The preemptive scheduler model lives in:
+
+```text
+specification/awkernel_async_lib/src/task/preemptive_spin
+```
+
+Use the normal LTL tests for non-kill scheduler behavior:
+
+```sh
+make -C specification/awkernel_async_lib/src/task/preemptive_spin clean run
+```
+
+Use the kill-specific reduced model for kill behavior:
+
+```sh
+make -C specification/awkernel_async_lib/src/task/preemptive_spin clean kill-test
+```
+
+`kill-test` enables `KILL_TEST`, uses a smaller task set, and should keep killer/kill-only state out of normal `make run`. Do not run `clean run` and `clean kill-test` concurrently in the same directory; both targets delete and regenerate `pan.*` files.
+
+## Scheduler failure patterns to check
+
+- Stale task IDs: a running snapshot may reference a task removed from the registry by `kill()`.
+- Terminal tasks: `Terminated` and `Panicked` tasks must not be requeued or selected for preemption.
+- Deferred kill: `Preempted` tasks should set `kill_pending` and terminate at a safe await/resume point.
+- Lock nesting: watch for self-deadlock around sleep/timer wake paths and global scheduler locks.
+- Pending preemption: queues may contain tasks that become terminal before the interrupt handler consumes them.
+
+## Generated files and commits
+
+Do not commit SPIN or QEMU generated artifacts unless explicitly requested:
+
+```text
+pan
+pan.*
+*.trail
+*_spin_nvr.tmp
+kill-test-*.log
+qemu-*.log
+```
+
+When committing scheduler work, include only source/model/test files relevant to the change. Leave unrelated dirty files untouched.

.claude/skills/awkernel-async-scheduler-testing

@@ -0,0 +1 @@
+../../.agents/skills/awkernel-async-scheduler-testing

.codex/skills/awkernel-async-scheduler-testing

@@ -0,0 +1 @@
+../../.agents/skills/awkernel-async-scheduler-testing

AGENTS.md

@@ -0,0 +1,54 @@
+# Repository Guidelines
+
+## Project Structure & Module Organization
+This repository is a Rust workspace (`Cargo.toml`) with these primary areas:
+
+- `kernel/`: core OS kernel crate.
+- `awkernel_lib/`, `awkernel_async_lib/`, `awkernel_drivers/`: shared kernel/runtime infrastructure.
+- `awkernel_aarch64/`, `x86bootdisk/`: architecture/platform support helpers.
+- `userland/`: user-space library and app support.
+- `applications/`: runnable samples/tests (`applications/tests/*`) and app crates.
+- `smoltcp/`: network stack crate used by kernel/user code.
+- `mdbook/`: documentation source; `docs/` stores generated docs output.
+- `specification/`: design and implementation notes.
+- `docker/`, `scripts/`, `targets/`, `misc/`: tooling, build config, boot artifacts, and platform files.
+
+## Build, Test, and Development Commands
+- `make x86_64 [RELEASE=1]`: build x86_64 kernel image.
+- `make aarch64 BSP=<raspi3|raspi4|raspi5|aarch64_virt> [RELEASE=1]`: build AArch64 targets.
+- `make riscv32` / `make riscv64`: build RISC-V targets.
+- `make qemu-x86_64`, `make qemu-aarch64-virt`, `make qemu-raspi3`: boot in QEMU.
+- `make check`: run check across kernel targets and std crates.
+- `make clippy`: run lints for major targets.
+- `make test`: run `test_awkernel_lib`, `test_awkernel_async_lib`, `test_awkernel_drivers`, `test_smoltcp`, `test_rd_gen_to_dags`.
+- `make docs`: build mdBook docs.
+- `make fmt`: run `cargo fmt`.
+- Direct aliases are in `.cargo/config.toml` (examples: `cargo +nightly-2026-06-13 test_awkernel_lib`, `cargo +nightly-2026-06-13 x86`, `cargo +nightly-2026-06-13 doc_x86`).
+
+## Coding Style & Naming Conventions
+- Rust 2021 edition, default rustfmt formatting (`cargo fmt`).
+- Use 4-space indentation and standard Rust naming:
+  - crates, modules, functions: `snake_case`.
+  - types/traits: `CamelCase`.
+  - test functions: `test_*`.
+- Prefer small, explicit feature-gated modules; avoid broad default features.
+- Keep architecture-specific code separated by crate and feature flags (`x86`, `aarch64`, `rv32`, `rv64`, `std`).
+
+## Testing Guidelines
+- Unit tests are in `mod tests` blocks under crate source and can be run per-package through cargo aliases (e.g., `cargo +nightly-2026-06-13 test_awkernel_lib`).
+- Integration-style workload tests are under `applications/tests/*`, typically invoked through the general `make test` suite.
+- For behavior validation requiring emulation, reproduce with matching QEMU target command and board (`qemu-...` targets).
+- Use `cargo +nightly-2026-06-13 clippy_x86` / `clippy_rv64` style aliases for target-specific linting.
+
+## Commit & Pull Request Guidelines
+- Use Conventional Commit style observed in history: `type(scope): short summary` (examples: `feat(async): ...`, `fix(task): ...`, `test(task): ...`).
+- Keep each commit focused to one logical change.
+- PRs should include:
+  - target architecture and commands run (`make`, `cargo`, QEMU target),
+  - rationale for API/behavior changes,
+  - test commands and results.
+- Link related issues when applicable and call out platform impact (`x86_64`, `aarch64`, `riscv32`, `riscv64`).
+
+## Security & Environment Notes
+- Repository uses nightly toolchain; ensure `rustup toolchain install nightly-2026-06-13` and target support are in place before builds.
+- x86 UEFI QEMU flows require `OVMF_PATH` to point at valid `code.fd` and `vars.fd` locations.

CLAUDE.md

@@ -0,0 +1,3 @@
+# CLAUDE.md
+
+@AGENTS.md

applications/awkernel_services/src/lib.rs

@@ -12,21 +12,21 @@ const BUFFERED_LOGGER_NAME: &str = "[Awkernel] buffered logger service";
 const DISPLAY_SERVICE_NAME: &str = "[Awkernel] display service";
 
 pub async fn run() {
-    awkernel_async_lib::spawn(
+    let _ = awkernel_async_lib::spawn(
         BUFFERED_LOGGER_NAME.into(),
         buffered_logger::run(),
         awkernel_async_lib::scheduler::SchedulerType::PrioritizedFIFO(0),
     )
     .await;
 
-    awkernel_async_lib::spawn(
+    let _ = awkernel_async_lib::spawn(
         NETWORK_SERVICE_NAME.into(),
         network_service::run(),
         awkernel_async_lib::scheduler::SchedulerType::PrioritizedFIFO(0),
     )
     .await;
 
-    awkernel_async_lib::spawn(
+    let _ = awkernel_async_lib::spawn(
         DISPLAY_SERVICE_NAME.into(),
         awkernel_display::run(),
         awkernel_async_lib::scheduler::SchedulerType::PrioritizedFIFO(0),

applications/awkernel_services/src/network_service.rs

@@ -16,14 +16,14 @@ type ChanProtoInterruptHandlerDual = Chan<(), <ProtoInterruptHandler as HasDual>
 pub async fn run() {
     log::info!("Starting {}.", crate::NETWORK_SERVICE_NAME);
 
-    awkernel_async_lib::spawn(
+    let _ = awkernel_async_lib::spawn(
         GARBAGE_COLLECTOR_NAME.into(),
         tcp_garbage_collector(),
         SchedulerType::PrioritizedFIFO(0),
     )
     .await;
 
-    awkernel_async_lib::spawn(
+    let _ = awkernel_async_lib::spawn(
         NETWORK_IF_POLLER_NAME.into(),
         network_interface_poller(),
         SchedulerType::PrioritizedFIFO(0),
@@ -137,7 +137,7 @@ async fn spawn_handlers(
             if_status.device_name,
         );
 
-        awkernel_async_lib::spawn(
+        let _ = awkernel_async_lib::spawn(
             name.into(),
             interrupt_handler(if_status.interface_id, irq, server),
             SchedulerType::PrioritizedFIFO(0),
@@ -155,7 +155,7 @@ async fn spawn_handlers(
             if_status.device_name,
         );
 
-        awkernel_async_lib::spawn(
+        let _ = awkernel_async_lib::spawn(
             name.into(),
             poll_handler(if_status.interface_id, server),
             SchedulerType::PrioritizedFIFO(0),
@@ -173,7 +173,7 @@ async fn spawn_handlers(
             if_status.device_name,
         );
 
-        awkernel_async_lib::spawn(
+        let _ = awkernel_async_lib::spawn(
             name.into(),
             tick_handler(if_status.interface_id, tick_msec, server),
             SchedulerType::PrioritizedFIFO(0),

applications/tests/test_task_kill/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "test_task_kill"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+log = "0.4"
+
+[dependencies.awkernel_async_lib]
+path = "../../../awkernel_async_lib"
+default-features = false
+
+[dependencies.awkernel_lib]
+path = "../../../awkernel_lib"
+default-features = false