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/graphology-utils/rename-graph-keys.js

@@ -0,0 +1,68 @@
+/**
+ * Graphology Rename Graph Keys
+ * =============================
+ *
+ * Helpers allowing you to rename (ie. change the key) of nodes & edges .
+ */
+var copyEdge = require('./add-edge.js').copyEdge;
+
+module.exports = function renameGraphKeys(
+  graph,
+  nodeKeyMapping,
+  edgeKeyMapping
+) {
+  if (typeof nodeKeyMapping === 'undefined') nodeKeyMapping = {};
+  if (typeof edgeKeyMapping === 'undefined') edgeKeyMapping = {};
+
+  var renamed = graph.nullCopy();
+
+  // Renaming nodes
+  graph.forEachNode(function (key, attr) {
+    var renamedKey = nodeKeyMapping[key];
+
+    if (typeof renamedKey === 'undefined') renamedKey = key;
+
+    renamed.addNode(renamedKey, attr);
+  });
+
+  // Renaming edges
+  var currentSource, currentSourceRenamed;
+
+  graph.forEachAssymetricAdjacencyEntry(function (
+    source,
+    target,
+    _sa,
+    _ta,
+    key,
+    attr,
+    undirected
+  ) {
+    // Leveraging the ordered adjacency to save lookups
+    if (source !== currentSource) {
+      currentSource = source;
+      currentSourceRenamed = nodeKeyMapping[source];
+
+      if (typeof currentSourceRenamed === 'undefined')
+        currentSourceRenamed = source;
+    }
+
+    var targetRenamed = nodeKeyMapping[target];
+
+    if (typeof targetRenamed === 'undefined') targetRenamed = target;
+
+    var renamedKey = edgeKeyMapping[key];
+
+    if (typeof renamedKey === 'undefined') renamedKey = key;
+
+    copyEdge(
+      renamed,
+      undirected,
+      renamedKey,
+      currentSourceRenamed,
+      targetRenamed,
+      attr
+    );
+  });
+
+  return renamed;
+};