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/yaml/dist/schema/yaml-1.1/set.d.ts

@@ -0,0 +1,28 @@
+import { Pair } from '../../nodes/Pair';
+import type { Scalar } from '../../nodes/Scalar';
+import type { ToJSContext } from '../../nodes/toJS';
+import { YAMLMap } from '../../nodes/YAMLMap';
+import type { Schema } from '../../schema/Schema';
+import type { StringifyContext } from '../../stringify/stringify';
+import type { CreateNodeContext } from '../../util';
+import type { CollectionTag } from '../types';
+export declare class YAMLSet<T = unknown> extends YAMLMap<T, Scalar<null> | null> {
+    static tag: string;
+    constructor(schema?: Schema);
+    add(key: T | Pair<T, Scalar<null> | null> | {
+        key: T;
+        value: Scalar<null> | null;
+    }): void;
+    /**
+     * If `keepPair` is `true`, returns the Pair matching `key`.
+     * Otherwise, returns the value of that Pair's key.
+     */
+    get(key: unknown, keepPair?: boolean): any;
+    set(key: T, value: boolean): void;
+    /** @deprecated Will throw; `value` must be boolean */
+    set(key: T, value: null): void;
+    toJSON(_?: unknown, ctx?: ToJSContext): any;
+    toString(ctx?: StringifyContext, onComment?: () => void, onChompKeep?: () => void): string;
+    static from(schema: Schema, iterable: unknown, ctx: CreateNodeContext): YAMLSet;
+}
+export declare const set: CollectionTag;