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/postcss-selector-parser/README.md

@@ -0,0 +1,82 @@
+# postcss-selector-parser [![test](https://github.com/postcss/postcss-selector-parser/actions/workflows/test.yml/badge.svg)](https://github.com/postcss/postcss-selector-parser/actions/workflows/test.yml)
+
+> Selector parser with built in methods for working with selector strings.
+
+## Install
+
+With [npm](https://npmjs.com/package/postcss-selector-parser) do:
+
+```
+npm install postcss-selector-parser
+```
+
+## Quick Start
+
+```js
+const parser = require('postcss-selector-parser');
+const transform = selectors => {
+    selectors.walk(selector => {
+        // do something with the selector
+        console.log(String(selector))
+    });
+};
+
+const transformed = parser(transform).processSync('h1, h2, h3');
+```
+
+To normalize selector whitespace:
+
+```js
+const parser = require('postcss-selector-parser');
+const normalized = parser().processSync('h1, h2, h3', {lossless: false});
+// -> h1,h2,h3
+```
+
+Async support is provided through `parser.process` and will resolve a Promise
+with the resulting selector string.
+
+## API
+
+Please see [API.md](API.md).
+
+## Security
+
+### Selector nesting depth (CVE-2026-9358)
+
+The parser walks the selector AST recursively, both when parsing and when
+serializing it back to a string (`.toString()`). In versions up to and
+including `7.1.1`, a selector with extreme nesting — for example thousands of
+nested `:not(...)` — could recurse deeply enough to overflow the call stack and
+throw `RangeError: Maximum call stack size exceeded`, a potential
+denial-of-service when processing untrusted CSS.
+
+This is now bounded by a maximum nesting depth (default: `256`). Beyond that
+depth, parsing and serialization throw a regular, catchable `Error` at a
+predictable point instead of relying on the runtime hitting its stack limit.
+The default is far above any realistic selector, so it does not affect normal
+use.
+
+**Practical impact is low.** The only attacker-controlled input is the selector
+string itself, which is now capped by the default limit. The limit is
+adjustable through the `maxNestingDepth` option, but that option is trusted
+configuration provided by the integrating code — it is never derived from the
+parsed CSS, so a malicious selector cannot change it:
+
+```js
+// Tighten the limit when parsing untrusted input:
+parser().processSync(untrustedSelector, {maxNestingDepth: 128});
+```
+
+Raising `maxNestingDepth` to a very large value is an explicit, informed choice
+and can reintroduce the stack-overflow risk in environments with a small call
+stack (e.g. browser workers). The default is recommended unless you have a
+specific need.
+
+## Credits
+
+* Huge thanks to Andrey Sitnik (@ai) for work on PostCSS which helped
+  accelerate this module's development.
+
+## License
+
+MIT