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/p-limit/index.js

@@ -0,0 +1,71 @@
+'use strict';
+const Queue = require('yocto-queue');
+
+const pLimit = concurrency => {
+	if (!((Number.isInteger(concurrency) || concurrency === Infinity) && concurrency > 0)) {
+		throw new TypeError('Expected `concurrency` to be a number from 1 and up');
+	}
+
+	const queue = new Queue();
+	let activeCount = 0;
+
+	const next = () => {
+		activeCount--;
+
+		if (queue.size > 0) {
+			queue.dequeue()();
+		}
+	};
+
+	const run = async (fn, resolve, ...args) => {
+		activeCount++;
+
+		const result = (async () => fn(...args))();
+
+		resolve(result);
+
+		try {
+			await result;
+		} catch {}
+
+		next();
+	};
+
+	const enqueue = (fn, resolve, ...args) => {
+		queue.enqueue(run.bind(null, fn, resolve, ...args));
+
+		(async () => {
+			// This function needs to wait until the next microtask before comparing
+			// `activeCount` to `concurrency`, because `activeCount` is updated asynchronously
+			// when the run function is dequeued and called. The comparison in the if-statement
+			// needs to happen asynchronously as well to get an up-to-date value for `activeCount`.
+			await Promise.resolve();
+
+			if (activeCount < concurrency && queue.size > 0) {
+				queue.dequeue()();
+			}
+		})();
+	};
+
+	const generator = (fn, ...args) => new Promise(resolve => {
+		enqueue(fn, resolve, ...args);
+	});
+
+	Object.defineProperties(generator, {
+		activeCount: {
+			get: () => activeCount
+		},
+		pendingCount: {
+			get: () => queue.size
+		},
+		clearQueue: {
+			value: () => {
+				queue.clear();
+			}
+		}
+	});
+
+	return generator;
+};
+
+module.exports = pLimit;