feat(runtime): scheduler-via-runSkill + Pi banter escalation + base-site (follow-ups)

Three closures of remaining PRD follow-ups, one merge:

1. Reflex scheduler now drives behaviour from the curriculum.
   - reflex.js: replaced ad-hoc techTreeReflex + autonomousReflex with
     curriculumReflex that dispatches the skill suggested by
     snapshot.curriculum.plan via runSkill. Per-skill backoff for
     missing_tool / missing_material / no_target / no_food_source /
     unsupported_version. recover() hint with `{hint:"wander"}` swaps
     the next tick to wander for 60 s.
   - Chain is now: defend > eat > sleep > curriculum > idle.
   - reflex.test.js: 11 new tests covering busy/disconnected,
     defend/eat preemption, dispatch by id, unknown-skill fallback,
     per-skill + wander-hint backoffs, onComplete updating backoff.

2. Pi escalation for ADDRESSED_BANTER with hard rate limit.
   - bot.js: when generateReply returns {escalate:true}, spawn askPi
     with bot state + last 5 lines from that speaker (redacted via
     chatMemory). Reply capped at 200 chars, sent as one chat line.
   - Rate cap: 6 calls/hour, 90 s min gap. Suppressed escalations
     log once and silently drop.

3. Phase 4 substrate.
   - runtime/locations.js: atomic JSON store
     (state/<host>/locations.json) with setLocation / getLocation /
     nearestLocation / removeLocation; 6 tests.
   - runtime/base-site.js: scoreCurrentPosition(bot) + pure scoreSite
     bundle (wood / stone / water / flatness / no-players /
     no-foreign-builds, owned-blocks excluded from claim penalty);
     6 tests.
   - runtime/skills/choose-base.js: village.choose-base skill — scores
     the current spot, writes locations.base if score ≥ 8, otherwise
     returns code:"too_weak" with a wander recover hint.
   - curriculum.js: new final milestone village.base-site fires
     village.choose-base until a base location exists.
   - bot.js: stamps snapshot.locations from listLocations() each tick
     so the curriculum can read it without coupling to disk.

docs/runtime.md updated with three new sections.
npm test now 116/116.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

runtime/skills/choose-base.js

@@ -0,0 +1,58 @@
+// village.choose-base — score the bot's current position as a candidate
+// base site, and if it clears the minimum bar, persist it under
+// state/<host>/locations.json as "base". The skill is intentionally
+// shallow: a single tick at the bot's current footing, no global scan.
+// The curriculum can dispatch it repeatedly while the bot wanders, and
+// the threshold means most calls will return `code: "too_weak"` and
+// move on.
+
+import { scoreCurrentPosition } from "../base-site.js";
+import { setLocation, getLocation } from "../locations.js";
+
+const MIN_BASE_SCORE = 8; // out of ~14 max; tuned to "good enough"
+
+export const skill = Object.freeze({
+	id: "village.choose-base",
+	title: "Score the current spot as a base candidate",
+	timeoutMs: 5_000,
+	preconditions(ctx) {
+		if (!ctx?.bot) return { ok: false, code: "no_bot", detail: "bot missing" };
+		// If we already have a base, this skill is a no-op the curriculum
+		// shouldn't be asking for. Defer gracefully.
+		if (getLocation("base")) return { ok: false, code: "already_have_base", detail: "base location already set" };
+		return { ok: true };
+	},
+	async execute(ctx) {
+		const result = scoreCurrentPosition(ctx.bot);
+		if (!result?.position) {
+			return { ok: false, code: "no_position", detail: "bot has no position", worldDelta: null };
+		}
+		if (result.score < MIN_BASE_SCORE) {
+			return {
+				ok: false,
+				code: "too_weak",
+				detail: { score: result.score, reasons: result.reasons },
+				worldDelta: null,
+			};
+		}
+		const loc = setLocation("base", {
+			x: result.position.x,
+			y: result.position.y,
+			z: result.position.z,
+			dimension: ctx.snapshot?.dimension ?? "overworld",
+			radius: 8,
+			note: `auto-chosen base, score=${result.score}`,
+		});
+		return {
+			ok: true,
+			code: "done",
+			detail: { location: loc, score: result.score, reasons: result.reasons },
+			worldDelta: { baseAt: { x: loc.x, y: loc.y, z: loc.z }, score: result.score },
+		};
+	},
+	recover(ctx, result) {
+		// Most failures (too_weak) want us to wander and re-evaluate.
+		if (result.code === "too_weak") return { hint: "wander", reason: "current spot doesn't pass base threshold" };
+		return null;
+	},
+});

runtime/skills/index.js

@@ -26,6 +26,7 @@ import { skill as chopLogs } from "./chop-logs.js";
 import { skill as eat } from "./eat.js";
 import { skill as wander } from "./wander.js";
 import { skill as gatherStone } from "./gather-stone.js";
+import { skill as chooseBase } from "./choose-base.js";
 import {
 	craftPlanksSkill,
 	craftSticksSkill,
@@ -55,6 +56,7 @@ register(chopLogs);
 register(eat);
 register(wander);
 register(gatherStone);
+register(chooseBase);
 register(craftPlanksSkill);
 register(craftSticksSkill);
 register(craftWoodenAxeSkill);