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/form-data/index.d.ts

@@ -0,0 +1,62 @@
+// Definitions by: Carlos Ballesteros Velasco <https://github.com/soywiz>
+//                 Leon Yu <https://github.com/leonyu>
+//                 BendingBender <https://github.com/BendingBender>
+//                 Maple Miao <https://github.com/mapleeit>
+
+/// <reference types="node" />
+import * as stream from 'stream';
+import * as http from 'http';
+
+export = FormData;
+
+// Extracted because @types/node doesn't export interfaces.
+interface ReadableOptions {
+  highWaterMark?: number;
+  encoding?: string;
+  objectMode?: boolean;
+  read?(this: stream.Readable, size: number): void;
+  destroy?(this: stream.Readable, error: Error | null, callback: (error: Error | null) => void): void;
+  autoDestroy?: boolean;
+}
+
+interface Options extends ReadableOptions {
+  writable?: boolean;
+  readable?: boolean;
+  dataSize?: number;
+  maxDataSize?: number;
+  pauseStreams?: boolean;
+}
+
+declare class FormData extends stream.Readable {
+  constructor(options?: Options);
+  append(key: string, value: any, options?: FormData.AppendOptions | string): void;
+  getHeaders(userHeaders?: FormData.Headers): FormData.Headers;
+  submit(
+    params: string | FormData.SubmitOptions,
+    callback?: (error: Error | null, response: http.IncomingMessage) => void
+  ): http.ClientRequest;
+  getBuffer(): Buffer;
+  setBoundary(boundary: string): void;
+  getBoundary(): string;
+  getLength(callback: (err: Error | null, length: number) => void): void;
+  getLengthSync(): number;
+  hasKnownLength(): boolean;
+}
+
+declare namespace FormData {
+  interface Headers {
+    [key: string]: any;
+  }
+
+  interface AppendOptions {
+    header?: string | Headers;
+    knownLength?: number;
+    filename?: string;
+    filepath?: string;
+    contentType?: string;
+  }
+
+  interface SubmitOptions extends http.RequestOptions {
+    protocol?: 'https:' | 'http:';
+  }
+}