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/w3c-xmlserializer/lib/constants.js

@@ -0,0 +1,44 @@
+"use strict";
+
+module.exports.NAMESPACES = {
+  HTML: "http://www.w3.org/1999/xhtml",
+  XML: "http://www.w3.org/XML/1998/namespace",
+  XMLNS: "http://www.w3.org/2000/xmlns/"
+};
+
+module.exports.NODE_TYPES = {
+  ELEMENT_NODE: 1,
+  ATTRIBUTE_NODE: 2, // historical
+  TEXT_NODE: 3,
+  CDATA_SECTION_NODE: 4,
+  ENTITY_REFERENCE_NODE: 5, // historical
+  ENTITY_NODE: 6, // historical
+  PROCESSING_INSTRUCTION_NODE: 7,
+  COMMENT_NODE: 8,
+  DOCUMENT_NODE: 9,
+  DOCUMENT_TYPE_NODE: 10,
+  DOCUMENT_FRAGMENT_NODE: 11,
+  NOTATION_NODE: 12 // historical
+};
+
+module.exports.VOID_ELEMENTS = new Set([
+  "area",
+  "base",
+  "basefont",
+  "bgsound",
+  "br",
+  "col",
+  "embed",
+  "frame",
+  "hr",
+  "img",
+  "input",
+  "keygen",
+  "link",
+  "menuitem",
+  "meta",
+  "param",
+  "source",
+  "track",
+  "wbr"
+]);