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/getPaths.js

@@ -0,0 +1,82 @@
+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Tobias Koppers @sokra
+*/
+
+"use strict";
+
+/** @typedef {import("./Resolver").FileSystem} FileSystem */
+/** @typedef {{ paths: string[], segments: string[] }} GetPathsResult */
+
+/**
+ * Walk `path` from tip to root, returning every ancestor directory (plus the
+ * input itself) in `paths`, and each corresponding segment name in `segments`.
+ *
+ * The return value may be shared across callers via `getPathsCached` — treat
+ * it as read-only. Callers that need to mutate (currently only
+ * `SymlinkPlugin`) should `slice()` the arrays locally before writing.
+ * @param {string} path path
+ * @returns {GetPathsResult} paths and segments
+ */
+function getPaths(path) {
+	if (path === "/") return { paths: ["/"], segments: [""] };
+	const parts = path.split(/(.*?[\\/]+)/);
+	const paths = [path];
+	const segments = [parts[parts.length - 1]];
+	let part = parts[parts.length - 1];
+	path = path.slice(0, Math.max(0, path.length - part.length - 1));
+	for (let i = parts.length - 2; i > 2; i -= 2) {
+		paths.push(path);
+		part = parts[i];
+		path = path.slice(0, Math.max(0, path.length - part.length)) || "/";
+		segments.push(part.slice(0, -1));
+	}
+	[, part] = parts;
+	segments.push(part);
+	paths.push(part);
+	return {
+		paths,
+		segments,
+	};
+}
+
+/**
+ * Per-filesystem memoization of `getPaths`. Kept in a standalone WeakMap
+ * rather than being hung off `resolver.pathCache` so that adding this cache
+ * does not change the hidden-class shape of `pathCache` — which is accessed
+ * on the hot path of every resolve as `resolver.pathCache.{join,dirname,
+ * basename}.fn(...)`. CodSpeed caught that shape change as a ~1–2%
+ * instruction-count regression on `cache-predicate`, so we keep pathCache
+ * shape-stable by owning this cache here instead.
+ *
+ * The cache lifetime is tied to the filesystem object (same invariant as
+ * `_pathCacheByFs` in `Resolver.js`): when the user swaps filesystems the
+ * entries become unreachable and get collected.
+ * @type {WeakMap<FileSystem, Map<string, GetPathsResult>>}
+ */
+const _getPathsCacheByFs = new WeakMap();
+
+/**
+ * Memoized `getPaths`. The returned object is shared across callers — do
+ * not mutate the `paths` or `segments` arrays in-place; `slice()` first if
+ * you need a mutable copy.
+ * @param {FileSystem} fileSystem filesystem used as the cache namespace
+ * @param {string} path path
+ * @returns {GetPathsResult} paths and segments
+ */
+function getPathsCached(fileSystem, path) {
+	let cache = _getPathsCacheByFs.get(fileSystem);
+	if (cache === undefined) {
+		cache = new Map();
+		_getPathsCacheByFs.set(fileSystem, cache);
+	} else {
+		const cached = cache.get(path);
+		if (cached !== undefined) return cached;
+	}
+	const result = getPaths(path);
+	cache.set(path, result);
+	return result;
+}
+
+module.exports = getPaths;
+module.exports.getPathsCached = getPathsCached;