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/linter/vfile.js

@@ -0,0 +1,115 @@
+/**
+ * @fileoverview Virtual file
+ * @author Nicholas C. Zakas
+ */
+
+"use strict";
+
+//-----------------------------------------------------------------------------
+// Type Definitions
+//-----------------------------------------------------------------------------
+
+/** @typedef {import("@eslint/core").File} File */
+
+//------------------------------------------------------------------------------
+// Helpers
+//------------------------------------------------------------------------------
+
+/**
+ * Determines if a given value has a byte order mark (BOM).
+ * @param {string|Uint8Array} value The value to check.
+ * @returns {boolean} `true` if the value has a BOM, `false` otherwise.
+ */
+function hasUnicodeBOM(value) {
+	return typeof value === "string"
+		? value.charCodeAt(0) === 0xfeff
+		: value[0] === 0xef && value[1] === 0xbb && value[2] === 0xbf;
+}
+
+/**
+ * Strips Unicode BOM from the given value.
+ * @param {string|Uint8Array} value The value to remove the BOM from.
+ * @returns {string|Uint8Array} The stripped value.
+ */
+function stripUnicodeBOM(value) {
+	if (!hasUnicodeBOM(value)) {
+		return value;
+	}
+
+	if (typeof value === "string") {
+		/*
+		 * Check Unicode BOM.
+		 * In JavaScript, string data is stored as UTF-16, so BOM is 0xFEFF.
+		 * http://www.ecma-international.org/ecma-262/6.0/#sec-unicode-format-control-characters
+		 */
+		return value.slice(1);
+	}
+
+	/*
+	 * In a Uint8Array, the BOM is represented by three bytes: 0xEF, 0xBB, and 0xBF,
+	 * so we can just remove the first three bytes.
+	 */
+	return value.slice(3);
+}
+
+//------------------------------------------------------------------------------
+// Exports
+//------------------------------------------------------------------------------
+
+/**
+ * Represents a virtual file inside of ESLint.
+ * @implements {File}
+ */
+class VFile {
+	/**
+	 * The file path including any processor-created virtual path.
+	 * @type {string}
+	 * @readonly
+	 */
+	path;
+
+	/**
+	 * The file path on disk.
+	 * @type {string}
+	 * @readonly
+	 */
+	physicalPath;
+
+	/**
+	 * The file contents.
+	 * @type {string|Uint8Array}
+	 * @readonly
+	 */
+	body;
+
+	/**
+	 * The raw body of the file, including a BOM if present.
+	 * @type {string|Uint8Array}
+	 * @readonly
+	 */
+	rawBody;
+
+	/**
+	 * Indicates whether the file has a byte order mark (BOM).
+	 * @type {boolean}
+	 * @readonly
+	 */
+	bom;
+
+	/**
+	 * Creates a new instance.
+	 * @param {string} path The file path.
+	 * @param {string|Uint8Array} body The file contents.
+	 * @param {Object} [options] Additional options.
+	 * @param {string} [options.physicalPath] The file path on disk.
+	 */
+	constructor(path, body, { physicalPath } = {}) {
+		this.path = path;
+		this.physicalPath = physicalPath ?? path;
+		this.bom = hasUnicodeBOM(body);
+		this.body = stripUnicodeBOM(body);
+		this.rawBody = body;
+	}
+}
+
+module.exports = { VFile };