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/parse/cst-visit.js

@@ -0,0 +1,97 @@
+const BREAK = Symbol('break visit');
+const SKIP = Symbol('skip children');
+const REMOVE = Symbol('remove item');
+/**
+ * Apply a visitor to a CST document or item.
+ *
+ * Walks through the tree (depth-first) starting from the root, calling a
+ * `visitor` function with two arguments when entering each item:
+ *   - `item`: The current item, which included the following members:
+ *     - `start: SourceToken[]` – Source tokens before the key or value,
+ *       possibly including its anchor or tag.
+ *     - `key?: Token | null` – Set for pair values. May then be `null`, if
+ *       the key before the `:` separator is empty.
+ *     - `sep?: SourceToken[]` – Source tokens between the key and the value,
+ *       which should include the `:` map value indicator if `value` is set.
+ *     - `value?: Token` – The value of a sequence item, or of a map pair.
+ *   - `path`: The steps from the root to the current node, as an array of
+ *     `['key' | 'value', number]` tuples.
+ *
+ * The return value of the visitor may be used to control the traversal:
+ *   - `undefined` (default): Do nothing and continue
+ *   - `visit.SKIP`: Do not visit the children of this token, continue with
+ *      next sibling
+ *   - `visit.BREAK`: Terminate traversal completely
+ *   - `visit.REMOVE`: Remove the current item, then continue with the next one
+ *   - `number`: Set the index of the next step. This is useful especially if
+ *     the index of the current token has changed.
+ *   - `function`: Define the next visitor for this item. After the original
+ *     visitor is called on item entry, next visitors are called after handling
+ *     a non-empty `key` and when exiting the item.
+ */
+function visit(cst, visitor) {
+    if ('type' in cst && cst.type === 'document')
+        cst = { start: cst.start, value: cst.value };
+    _visit(Object.freeze([]), cst, visitor);
+}
+// Without the `as symbol` casts, TS declares these in the `visit`
+// namespace using `var`, but then complains about that because
+// `unique symbol` must be `const`.
+/** Terminate visit traversal completely */
+visit.BREAK = BREAK;
+/** Do not visit the children of the current item */
+visit.SKIP = SKIP;
+/** Remove the current item */
+visit.REMOVE = REMOVE;
+/** Find the item at `path` from `cst` as the root */
+visit.itemAtPath = (cst, path) => {
+    let item = cst;
+    for (const [field, index] of path) {
+        const tok = item?.[field];
+        if (tok && 'items' in tok) {
+            item = tok.items[index];
+        }
+        else
+            return undefined;
+    }
+    return item;
+};
+/**
+ * Get the immediate parent collection of the item at `path` from `cst` as the root.
+ *
+ * Throws an error if the collection is not found, which should never happen if the item itself exists.
+ */
+visit.parentCollection = (cst, path) => {
+    const parent = visit.itemAtPath(cst, path.slice(0, -1));
+    const field = path[path.length - 1][0];
+    const coll = parent?.[field];
+    if (coll && 'items' in coll)
+        return coll;
+    throw new Error('Parent collection not found');
+};
+function _visit(path, item, visitor) {
+    let ctrl = visitor(item, path);
+    if (typeof ctrl === 'symbol')
+        return ctrl;
+    for (const field of ['key', 'value']) {
+        const token = item[field];
+        if (token && 'items' in token) {
+            for (let i = 0; i < token.items.length; ++i) {
+                const ci = _visit(Object.freeze(path.concat([[field, i]])), token.items[i], visitor);
+                if (typeof ci === 'number')
+                    i = ci - 1;
+                else if (ci === BREAK)
+                    return BREAK;
+                else if (ci === REMOVE) {
+                    token.items.splice(i, 1);
+                    i -= 1;
+                }
+            }
+            if (typeof ctrl === 'function' && field === 'key')
+                ctrl = ctrl(item, path);
+        }
+    }
+    return typeof ctrl === 'function' ? ctrl(item, path) : ctrl;
+}
+
+export { visit };