v0.3.0-rc.3: event-driven awareness + skill pre-emption

Adds a reactive layer on top of the polling reflex. The bot now
notices environmental shocks (forced moves, HP plunges, hostile
spawns) within ~100ms instead of waiting for the next DISPATCH tick,
and the in-flight skill is preempted so the next reflex cycle can
re-plan against the current world state.

This is the rc that wires the "rc.1 plumbing + rc.2 manifesto" into
a feedback loop:
  - awareness fires preempt → dispatch aborts
  - reflex tick re-evaluates → manifesto walks the ladder
  - new dispatch picks the right skill for the new world state

Pieces:

- runtime/awareness/events.js (new) — bot.on listeners:
  - move: single-tick Δposition ≥ 5 blocks → forced_move flag + preempt
  - health: HP drop ≥ 2 → health_plunge flag + preempt
  - entitySpawn: hostile mob within 12 blocks → hostile_added + preempt
  - blockUpdate: nearby block change → env_changed flag (no preempt,
    throttled 800ms; otherwise gather skills would self-preempt
    every dig)

- runtime/skills/index.js — RUNNER_CODES.PREEMPTED + raceWithAbort()
  wraps every execute() against ctx.abortSignal. Existing skills get
  preemption for free; they don't have to check the signal manually.

- runtime/bot.js:
  - dispatchAction creates a fresh AbortController per dispatch and
    stores it on reflexCtx.currentAbort
  - attachAwareness fires controller.abort() when something disrupts
    the active skill; runSkill returns code: "preempted" and the
    reflex moves on
  - reflexCtx.lastPreempt records the most recent shock

Tests: 332 green (was 315 on rc.2, +17 new):
- runtime/awareness/events.test.js — 12 tests (each event type +
  thresholds + throttling + passive-mob filter)
- runtime/skills/contract.test.js — 3 abortSignal tests
  (mid-flight, pre-armed, clean signal)

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

runtime/skills/index.js

@@ -118,6 +118,7 @@ export const RUNNER_CODES = Object.freeze({
 	TIMEOUT: "timeout",
 	THREW: "threw",
 	VALIDATION_FAILED: "validation_failed",
+	PREEMPTED: "preempted",
 	DONE: "done",
 });
 
@@ -139,6 +140,42 @@ function withTimeout(promise, ms, label) {
 	return Promise.race([promise, timeout]).finally(() => clearTimeout(timer));
 }
 
+// v0.3.0-rc.3 — wrap execute() so that if ctx.abortSignal fires we
+// stop awaiting (and surface code: "preempted"). The skill itself
+// doesn't need to read the signal — the race below ensures runSkill
+// returns control to the reflex within one microtask of abort(). The
+// skill's own async work may continue in the background harmlessly,
+// because the next dispatch will overwrite any shared state.
+function raceWithAbort(promise, signal) {
+	if (!signal) return promise;
+	if (signal.aborted) {
+		return Promise.reject(Object.assign(new Error("preempted"), { _preempted: true }));
+	}
+	return new Promise((resolve, reject) => {
+		let settled = false;
+		const onAbort = () => {
+			if (settled) return;
+			settled = true;
+			reject(Object.assign(new Error("preempted"), { _preempted: true }));
+		};
+		signal.addEventListener("abort", onAbort, { once: true });
+		promise.then(
+			(v) => {
+				if (settled) return;
+				settled = true;
+				signal.removeEventListener?.("abort", onAbort);
+				resolve(v);
+			},
+			(e) => {
+				if (settled) return;
+				settled = true;
+				signal.removeEventListener?.("abort", onAbort);
+				reject(e);
+			},
+		);
+	});
+}
+
 // Drive one skill through its full lifecycle. The caller (typically reflex.js
 // or, eventually, a higher-level scheduler) decides when to invoke; runSkill
 // only owns the contract enforcement.
@@ -172,12 +209,19 @@ export async function runSkill(id, ctx, args = {}) {
 	const timeoutMs = skill.timeoutMs ?? 30_000;
 	let raw;
 	try {
-		raw = await withTimeout(skill.execute(ctx, args), timeoutMs, `skill(${id})`);
+		raw = await withTimeout(
+			raceWithAbort(skill.execute(ctx, args), ctx?.abortSignal),
+			timeoutMs,
+			`skill(${id})`,
+		);
 	} catch (e) {
 		const isTimeout = /timed out after/.test(e.message);
+		const isPreempted = e?._preempted === true;
 		const result = {
 			ok: false,
-			code: isTimeout ? RUNNER_CODES.TIMEOUT : RUNNER_CODES.THREW,
+			code: isPreempted
+				? RUNNER_CODES.PREEMPTED
+				: isTimeout ? RUNNER_CODES.TIMEOUT : RUNNER_CODES.THREW,
 			detail: e.message,
 			worldDelta: null,
 		};