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-unassigned-vars.js

@@ -0,0 +1,80 @@
+/**
+ * @fileoverview Rule to flag variables that are never assigned
+ * @author Jacob Bandes-Storch <https://github.com/jtbandes>
+ */
+"use strict";
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+/** @type {import('../types').Rule.RuleModule} */
+module.exports = {
+	meta: {
+		type: "problem",
+		dialects: ["typescript", "javascript"],
+		language: "javascript",
+
+		docs: {
+			description:
+				"Disallow `let` or `var` variables that are read but never assigned",
+			recommended: false,
+			url: "https://eslint.org/docs/latest/rules/no-unassigned-vars",
+		},
+
+		schema: [],
+		messages: {
+			unassigned:
+				"'{{name}}' is always 'undefined' because it's never assigned.",
+		},
+	},
+
+	create(context) {
+		const sourceCode = context.sourceCode;
+		let insideDeclareModule = false;
+
+		return {
+			"TSModuleDeclaration[declare=true]"() {
+				insideDeclareModule = true;
+			},
+			"TSModuleDeclaration[declare=true]:exit"() {
+				insideDeclareModule = false;
+			},
+			VariableDeclarator(node) {
+				/** @type {import('estree').VariableDeclaration} */
+				const declaration = node.parent;
+				const shouldSkip =
+					node.init ||
+					node.id.type !== "Identifier" ||
+					declaration.kind === "const" ||
+					declaration.declare ||
+					insideDeclareModule;
+				if (shouldSkip) {
+					return;
+				}
+				const [variable] = sourceCode.getDeclaredVariables(node);
+				if (!variable) {
+					return;
+				}
+				let hasRead = false;
+				for (const reference of variable.references) {
+					if (reference.isWrite()) {
+						return;
+					}
+					if (reference.isRead()) {
+						hasRead = true;
+					}
+				}
+				if (!hasRead) {
+					// Variables that are never read should be flagged by no-unused-vars instead
+					return;
+				}
+				context.report({
+					node,
+					messageId: "unassigned",
+					data: { name: node.id.name },
+				});
+			},
+		};
+	},
+};