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/eslint/lib/rules/no-multi-assign.js

@@ -0,0 +1,66 @@
+/**
+ * @fileoverview Rule to check use of chained assignment expressions
+ * @author Stewart Rand
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+/** @type {import('../types').Rule.RuleModule} */
+module.exports = {
+	meta: {
+		type: "suggestion",
+
+		defaultOptions: [
+			{
+				ignoreNonDeclaration: false,
+			},
+		],
+
+		docs: {
+			description: "Disallow use of chained assignment expressions",
+			recommended: false,
+			url: "https://eslint.org/docs/latest/rules/no-multi-assign",
+		},
+
+		schema: [
+			{
+				type: "object",
+				properties: {
+					ignoreNonDeclaration: {
+						type: "boolean",
+					},
+				},
+				additionalProperties: false,
+			},
+		],
+
+		messages: {
+			unexpectedChain: "Unexpected chained assignment.",
+		},
+	},
+
+	create(context) {
+		const [{ ignoreNonDeclaration }] = context.options;
+		const selectors = [
+			"VariableDeclarator > AssignmentExpression.init",
+			"PropertyDefinition > AssignmentExpression.value",
+		];
+
+		if (!ignoreNonDeclaration) {
+			selectors.push("AssignmentExpression > AssignmentExpression.right");
+		}
+
+		return {
+			[selectors](node) {
+				context.report({
+					node,
+					messageId: "unexpectedChain",
+				});
+			},
+		};
+	},
+};