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/enhanced-resolve/lib/RestrictionsPlugin.js

@@ -0,0 +1,86 @@
+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Ivan Kopeykin @vankop
+*/
+
+"use strict";
+
+const { isInside, normalize } = require("./util/path");
+
+/** @typedef {import("./Resolver")} Resolver */
+/** @typedef {import("./Resolver").ResolveStepHook} ResolveStepHook */
+
+/**
+ * @typedef {object} PathRestriction
+ * @property {"path"} type type of the restriction
+ * @property {string} rule normalized path the request has to be inside of
+ */
+
+/**
+ * @typedef {object} RegExpRestriction
+ * @property {"regexp"} type type of the restriction
+ * @property {RegExp} rule pattern the request has to match
+ */
+
+/** @typedef {PathRestriction | RegExpRestriction} Restriction */
+
+module.exports = class RestrictionsPlugin {
+	/**
+	 * @param {string | ResolveStepHook} source source
+	 * @param {Set<string | RegExp>} restrictions restrictions
+	 */
+	constructor(source, restrictions) {
+		this.source = source;
+		this.restrictions = restrictions;
+		// Restrictions never change, so bringing them into the shape requests
+		// arrive in is done once here instead of on every request.
+		/** @type {Restriction[]} */
+		this._restrictions = [];
+		for (const rule of restrictions) {
+			this._restrictions.push(
+				typeof rule === "string"
+					? { type: "path", rule: normalize(rule) }
+					: { type: "regexp", rule },
+			);
+		}
+	}
+
+	/**
+	 * @param {Resolver} resolver the resolver
+	 * @returns {void}
+	 */
+	apply(resolver) {
+		resolver
+			.getHook(this.source)
+			.tapAsync("RestrictionsPlugin", (request, resolveContext, callback) => {
+				if (typeof request.path === "string") {
+					const { path } = request;
+					for (const restriction of this._restrictions) {
+						if (restriction.type === "path") {
+							if (isInside(restriction.rule, path)) continue;
+							if (resolveContext.log) {
+								resolveContext.log(
+									`${path} is not inside of the restriction ${restriction.rule}`,
+								);
+							}
+						} else {
+							if (restriction.rule.test(path)) continue;
+							if (resolveContext.log) {
+								resolveContext.log(
+									`${path} doesn't match the restriction ${restriction.rule}`,
+								);
+							}
+						}
+						// Target existed (FileExistsPlugin already passed) but is
+						// outside the jail; signal ExportsFieldPlugin to fall back.
+						if (request.__restrictionsMarker) {
+							request.__restrictionsMarker.blocked = true;
+						}
+						return callback(null, null);
+					}
+				}
+
+				callback();
+			});
+	}
+};