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/find-up/index.js

@@ -0,0 +1,89 @@
+'use strict';
+const path = require('path');
+const locatePath = require('locate-path');
+const pathExists = require('path-exists');
+
+const stop = Symbol('findUp.stop');
+
+module.exports = async (name, options = {}) => {
+	let directory = path.resolve(options.cwd || '');
+	const {root} = path.parse(directory);
+	const paths = [].concat(name);
+
+	const runMatcher = async locateOptions => {
+		if (typeof name !== 'function') {
+			return locatePath(paths, locateOptions);
+		}
+
+		const foundPath = await name(locateOptions.cwd);
+		if (typeof foundPath === 'string') {
+			return locatePath([foundPath], locateOptions);
+		}
+
+		return foundPath;
+	};
+
+	// eslint-disable-next-line no-constant-condition
+	while (true) {
+		// eslint-disable-next-line no-await-in-loop
+		const foundPath = await runMatcher({...options, cwd: directory});
+
+		if (foundPath === stop) {
+			return;
+		}
+
+		if (foundPath) {
+			return path.resolve(directory, foundPath);
+		}
+
+		if (directory === root) {
+			return;
+		}
+
+		directory = path.dirname(directory);
+	}
+};
+
+module.exports.sync = (name, options = {}) => {
+	let directory = path.resolve(options.cwd || '');
+	const {root} = path.parse(directory);
+	const paths = [].concat(name);
+
+	const runMatcher = locateOptions => {
+		if (typeof name !== 'function') {
+			return locatePath.sync(paths, locateOptions);
+		}
+
+		const foundPath = name(locateOptions.cwd);
+		if (typeof foundPath === 'string') {
+			return locatePath.sync([foundPath], locateOptions);
+		}
+
+		return foundPath;
+	};
+
+	// eslint-disable-next-line no-constant-condition
+	while (true) {
+		const foundPath = runMatcher({...options, cwd: directory});
+
+		if (foundPath === stop) {
+			return;
+		}
+
+		if (foundPath) {
+			return path.resolve(directory, foundPath);
+		}
+
+		if (directory === root) {
+			return;
+		}
+
+		directory = path.dirname(directory);
+	}
+};
+
+module.exports.exists = pathExists;
+
+module.exports.sync.exists = pathExists.sync;
+
+module.exports.stop = stop;