feat(runtime): script-driven reflex daemon + Ink TUI dashboard

Pure-Pi runtime had three failure modes in practice:
  - slow: 20-60s per decision because LLM was in the hot path
  - expensive: every tick (defend, eat, idle) paid for a reasoning pass
  - invisible: required tmux capture-pane to know what the bot was doing

New runtime/ layer is a long-running Node daemon that owns the MC
connection, ticks a priority-ordered reflex chain (defend > eat > sleep
> idle) with NO LLM in the hot path, and exposes status + commands over
a Unix-socket IPC. tui/ is an Ink dashboard that attaches over IPC and
can detach freely — multiple TUI clients can connect at once.

Pi/Codex are still available, but as on-demand escalation: TUI hotkey
'a' spawns `pi -p "<prompt>"` as a subprocess and streams stdout into
the dashboard. The self-improvement loop (proposals → operator approval
→ Pi-driven patch → hot reload) is documented in docs/runtime.md but
not yet wired.

Reflex bodies are stubs today — they log decisions but don't drive
Mineflayer actions yet. The priority chain, IPC contract, and TUI are
fully working; subsequent commits will fill in defend/eat/sleep bodies
and wire automatic escalation.

Run with `npm run bot` + `npm run tui`. Pi-only fallback stays at
`npm run agent`.

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

runtime/config.js

@@ -0,0 +1,48 @@
+import { config as loadDotenv } from "dotenv";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+export const REPO_ROOT = path.resolve(__dirname, "..");
+
+loadDotenv({ path: path.join(REPO_ROOT, ".env") });
+
+function req(name) {
+	const v = process.env[name]?.trim();
+	if (!v) throw new Error(`Missing required env var: ${name}`);
+	return v;
+}
+
+function opt(name, fallback = "") {
+	return process.env[name]?.trim() || fallback;
+}
+
+const host = req("MC_HOST");
+const port = Number.parseInt(opt("MC_PORT", "25565"), 10);
+const username = req("MC_USERNAME");
+
+export const config = Object.freeze({
+	host,
+	port,
+	username,
+	version: opt("MC_VERSION", "1.21.5"),
+	authMode: opt("MC_AUTH_MODE", "offline"),
+	authmePassword: opt("MC_AUTHME_PASSWORD", ""),
+	operators: opt("OPERATOR_USERNAMES", "")
+		.split(",")
+		.map((s) => s.trim().toLowerCase())
+		.filter(Boolean),
+	tickIntervalMs: Math.max(1, Number.parseInt(opt("TICK_INTERVAL_SECONDS", "3"), 10)) * 1000,
+	chatRateLimitPerMin: Number.parseInt(opt("CHAT_RATE_LIMIT_PER_MIN", "15"), 10),
+});
+
+export const serverKey = `${host}_${port}`;
+export const stateDir = path.join(REPO_ROOT, "state", serverKey);
+export const socketPath = path.join(stateDir, "bot.sock");
+
+// Redacted env view for logs — never include the AuthMe password.
+export function redactedConfig() {
+	const { authmePassword, ...rest } = config;
+	return { ...rest, authmePassword: authmePassword ? "***" : "(unset)" };
+}