feat: Phase 1 — extract the client (web SPA + desktop) to dtoro/oikos-web

Problem: the hexagonal refactor churns the backend tree for nine more
phases; the UI delivery stack (web/ SPA, cmd/desktop Wails wrapper,
compose/web image) must move to its own repo first so doc/layout
rewrites land once on a backend-only tree.

Change:
- New repo git.hubris.network/dtoro/oikos-web (v0.33.0): web/, desktop/
  (updateURL repointed to oikos-web releases), compose/, own CI (web +
  desktop jobs), own deploy script (CI-green gate, TOCTOU guard,
  version-tagged images, prune-to-3), own webhook receiver on :9798 +
  launchd unit, own compose project publishing the same 8091:80.
- Cutover executed on mac-mini in order: oikos stack's web service
  stopped+removed, oikos-web project brought up on 8091; outer Caddy
  untouched (targets the published port) — serving + Authentik flow +
  /wails 404 quirk verified post-cutover.
- Stripped from oikos: web/, cmd/desktop/, compose/web/, desktop CI
  workflow, ci.yml web job, Makefile ui/desktop/desktop-package/install
  targets, the compose web service, oikos-web from deploy.sh's fallback
  prune list; wails + go-keyring dropped from go.mod, vendor synced.
- README / CONTRIBUTING / AGENTS.md / .agents dev+operations docs now
  point at the new repo; mbse + mascot design docs carry a path note.

Risk: production SPA serving depends on the new pipeline now; rollback
is versioned-image re-up of the old web service from a pre-split
checkout (port 8091). Desktop builds installed before the split still
check dtoro/oikos releases — one manual reinstall, noted in the
oikos-web release notes.

Verification: go vet, make test (race), make generate-check, golangci
(no new findings; baseline down 400→365); post-cutover curls —
localhost:8091 200, /wails/runtime.js 404, outer Caddy 302 Authentik.

web/node_modules/tinypool/dist/entry/process.js

@@ -0,0 +1,72 @@
+import { stderr, stdout } from "../utils-De75vAgL.js";
+import { getHandler, throwInNextTick } from "../utils-B--2TaWv.js";
+
+//#region src/entry/process.ts
+process.__tinypool_state__ = {
+	isChildProcess: true,
+	isTinypoolWorker: true,
+	workerData: null,
+	workerId: Number(process.env.TINYPOOL_WORKER_ID)
+};
+const memoryUsage = process.memoryUsage.bind(process);
+const send = process.send.bind(process);
+process.on("message", (message) => {
+	if (!message || !message.__tinypool_worker_message__) return;
+	if (message.source === "pool") {
+		const { filename, name } = message;
+		(async function() {
+			if (filename !== null) await getHandler(filename, name);
+			send({
+				ready: true,
+				source: "pool",
+				__tinypool_worker_message__: true
+			}, () => {});
+		})().catch(throwInNextTick);
+		return;
+	}
+	if (message.source === "port") {
+		onMessage(message).catch(throwInNextTick);
+		return;
+	}
+	throw new Error(`Unexpected TinypoolWorkerMessage ${JSON.stringify(message)}`);
+});
+async function onMessage(message) {
+	const { taskId, task, filename, name } = message;
+	let response;
+	try {
+		const handler = await getHandler(filename, name);
+		if (handler === null) throw new Error(`No handler function "${name}" exported from "${filename}"`);
+		const result = await handler(task);
+		response = {
+			source: "port",
+			__tinypool_worker_message__: true,
+			taskId,
+			result,
+			error: null,
+			usedMemory: memoryUsage().heapUsed
+		};
+		if (stdout()?.writableLength > 0) await new Promise((resolve) => process.stdout.write("", resolve));
+		if (stderr()?.writableLength > 0) await new Promise((resolve) => process.stderr.write("", resolve));
+	} catch (error) {
+		response = {
+			source: "port",
+			__tinypool_worker_message__: true,
+			taskId,
+			result: null,
+			error: serializeError(error),
+			usedMemory: memoryUsage().heapUsed
+		};
+	}
+	send(response);
+}
+function serializeError(error) {
+	if (error instanceof Error) return {
+		...error,
+		name: error.name,
+		stack: error.stack,
+		message: error.message
+	};
+	return String(error);
+}
+
+//#endregion