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/browser/dist/nodes/addPairToJSMap.js

@@ -0,0 +1,63 @@
+import { warn } from '../log.js';
+import { isMergeKey, addMergeToJSMap } from '../schema/yaml-1.1/merge.js';
+import { createStringifyContext } from '../stringify/stringify.js';
+import { isNode } from './identity.js';
+import { toJS } from './toJS.js';
+
+function addPairToJSMap(ctx, map, { key, value }) {
+    if (isNode(key) && key.addToJSMap)
+        key.addToJSMap(ctx, map, value);
+    // TODO: Should drop this special case for bare << handling
+    else if (isMergeKey(ctx, key))
+        addMergeToJSMap(ctx, map, value);
+    else {
+        const jsKey = toJS(key, '', ctx);
+        if (map instanceof Map) {
+            map.set(jsKey, toJS(value, jsKey, ctx));
+        }
+        else if (map instanceof Set) {
+            map.add(jsKey);
+        }
+        else {
+            const stringKey = stringifyKey(key, jsKey, ctx);
+            const jsValue = toJS(value, stringKey, ctx);
+            if (stringKey in map)
+                Object.defineProperty(map, stringKey, {
+                    value: jsValue,
+                    writable: true,
+                    enumerable: true,
+                    configurable: true
+                });
+            else
+                map[stringKey] = jsValue;
+        }
+    }
+    return map;
+}
+function stringifyKey(key, jsKey, ctx) {
+    if (jsKey === null)
+        return '';
+    // eslint-disable-next-line @typescript-eslint/no-base-to-string
+    if (typeof jsKey !== 'object')
+        return String(jsKey);
+    if (isNode(key) && ctx?.doc) {
+        const strCtx = createStringifyContext(ctx.doc, {});
+        strCtx.anchors = new Set();
+        for (const node of ctx.anchors.keys())
+            strCtx.anchors.add(node.anchor);
+        strCtx.inFlow = true;
+        strCtx.inStringifyKey = true;
+        const strKey = key.toString(strCtx);
+        if (!ctx.mapKeyWarned) {
+            let jsonStr = JSON.stringify(strKey);
+            if (jsonStr.length > 40)
+                jsonStr = jsonStr.substring(0, 36) + '..."';
+            warn(ctx.doc.options.logLevel, `Keys with collection values will be stringified due to JS Object restrictions: ${jsonStr}. Set mapAsMap: true to use object keys.`);
+            ctx.mapKeyWarned = true;
+        }
+        return strKey;
+    }
+    return JSON.stringify(jsKey);
+}
+
+export { addPairToJSMap };