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/doc/createNode.js

@@ -0,0 +1,90 @@
+'use strict';
+
+var Alias = require('../nodes/Alias.js');
+var identity = require('../nodes/identity.js');
+var Scalar = require('../nodes/Scalar.js');
+
+const defaultTagPrefix = 'tag:yaml.org,2002:';
+function findTagObject(value, tagName, tags) {
+    if (tagName) {
+        const match = tags.filter(t => t.tag === tagName);
+        const tagObj = match.find(t => !t.format) ?? match[0];
+        if (!tagObj)
+            throw new Error(`Tag ${tagName} not found`);
+        return tagObj;
+    }
+    return tags.find(t => t.identify?.(value) && !t.format);
+}
+function createNode(value, tagName, ctx) {
+    if (identity.isDocument(value))
+        value = value.contents;
+    if (identity.isNode(value))
+        return value;
+    if (identity.isPair(value)) {
+        const map = ctx.schema[identity.MAP].createNode?.(ctx.schema, null, ctx);
+        map.items.push(value);
+        return map;
+    }
+    if (value instanceof String ||
+        value instanceof Number ||
+        value instanceof Boolean ||
+        (typeof BigInt !== 'undefined' && value instanceof BigInt) // not supported everywhere
+    ) {
+        // https://tc39.es/ecma262/#sec-serializejsonproperty
+        value = value.valueOf();
+    }
+    const { aliasDuplicateObjects, onAnchor, onTagObj, schema, sourceObjects } = ctx;
+    // Detect duplicate references to the same object & use Alias nodes for all
+    // after first. The `ref` wrapper allows for circular references to resolve.
+    let ref = undefined;
+    if (aliasDuplicateObjects && value && typeof value === 'object') {
+        ref = sourceObjects.get(value);
+        if (ref) {
+            ref.anchor ?? (ref.anchor = onAnchor(value));
+            return new Alias.Alias(ref.anchor);
+        }
+        else {
+            ref = { anchor: null, node: null };
+            sourceObjects.set(value, ref);
+        }
+    }
+    if (tagName?.startsWith('!!'))
+        tagName = defaultTagPrefix + tagName.slice(2);
+    let tagObj = findTagObject(value, tagName, schema.tags);
+    if (!tagObj) {
+        if (value && typeof value.toJSON === 'function') {
+            // eslint-disable-next-line @typescript-eslint/no-unsafe-call
+            value = value.toJSON();
+        }
+        if (!value || typeof value !== 'object') {
+            const node = new Scalar.Scalar(value);
+            if (ref)
+                ref.node = node;
+            return node;
+        }
+        tagObj =
+            value instanceof Map
+                ? schema[identity.MAP]
+                : Symbol.iterator in Object(value)
+                    ? schema[identity.SEQ]
+                    : schema[identity.MAP];
+    }
+    if (onTagObj) {
+        onTagObj(tagObj);
+        delete ctx.onTagObj;
+    }
+    const node = tagObj?.createNode
+        ? tagObj.createNode(ctx.schema, value, ctx)
+        : typeof tagObj?.nodeClass?.from === 'function'
+            ? tagObj.nodeClass.from(ctx.schema, value, ctx)
+            : new Scalar.Scalar(value);
+    if (tagName)
+        node.tag = tagName;
+    else if (!tagObj.default)
+        node.tag = tagObj.tag;
+    if (ref)
+        ref.node = node;
+    return node;
+}
+
+exports.createNode = createNode;