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-empty-character-class.js

@@ -0,0 +1,83 @@
+/**
+ * @fileoverview Rule to flag the use of empty character classes in regular expressions
+ * @author Ian Christian Myers
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const { RegExpParser, visitRegExpAST } = require("@eslint-community/regexpp");
+
+//------------------------------------------------------------------------------
+// Helpers
+//------------------------------------------------------------------------------
+
+const parser = new RegExpParser();
+const QUICK_TEST_REGEX = /\[\]/u;
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+/** @type {import('../types').Rule.RuleModule} */
+module.exports = {
+	meta: {
+		type: "problem",
+
+		docs: {
+			description:
+				"Disallow empty character classes in regular expressions",
+			recommended: true,
+			url: "https://eslint.org/docs/latest/rules/no-empty-character-class",
+		},
+
+		schema: [],
+
+		messages: {
+			unexpected: "Empty class.",
+		},
+	},
+
+	create(context) {
+		return {
+			"Literal[regex]"(node) {
+				const { pattern, flags } = node.regex;
+
+				if (!QUICK_TEST_REGEX.test(pattern)) {
+					return;
+				}
+
+				let regExpAST;
+
+				try {
+					regExpAST = parser.parsePattern(
+						pattern,
+						0,
+						pattern.length,
+						{
+							unicode: flags.includes("u"),
+							unicodeSets: flags.includes("v"),
+						},
+					);
+				} catch {
+					// Ignore regular expressions that regexpp cannot parse
+					return;
+				}
+
+				visitRegExpAST(regExpAST, {
+					onCharacterClassEnter(characterClass) {
+						if (
+							!characterClass.negate &&
+							characterClass.elements.length === 0
+						) {
+							context.report({ node, messageId: "unexpected" });
+						}
+					},
+				});
+			},
+		};
+	},
+};