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/lightningcss/node/index.js

@@ -0,0 +1,59 @@
+let parts = [process.platform, process.arch];
+if (process.platform === 'linux') {
+  const { MUSL, familySync } = require('detect-libc');
+  const family = familySync();
+  if (family === MUSL) {
+    parts.push('musl');
+  } else if (process.arch === 'arm') {
+    parts.push('gnueabihf');
+  } else {
+    parts.push('gnu');
+  }
+} else if (process.platform === 'win32') {
+  parts.push('msvc');
+}
+
+let native;
+try {
+  native = require(`lightningcss-${parts.join('-')}`);
+} catch (err) {
+  native = require(`../lightningcss.${parts.join('-')}.node`);
+}
+
+module.exports.transform = wrap(native.transform);
+module.exports.transformStyleAttribute = wrap(native.transformStyleAttribute);
+module.exports.bundle = wrap(native.bundle);
+module.exports.bundleAsync = wrap(native.bundleAsync);
+module.exports.browserslistToTargets = require('./browserslistToTargets');
+module.exports.composeVisitors = require('./composeVisitors');
+module.exports.Features = require('./flags').Features;
+
+function wrap(call) {
+  return (options) => {
+    if (typeof options.visitor === 'function') {
+      let deps = [];
+      options.visitor = options.visitor({
+        addDependency(dep) {
+          deps.push(dep);
+        }
+      });
+
+      let result = call(options);
+      if (result instanceof Promise) {
+        result = result.then(res => {
+          if (deps.length) {
+            res.dependencies ??= [];
+            res.dependencies.push(...deps);
+          }
+          return res;
+        });
+      } else if (deps.length) {
+        result.dependencies ??= [];
+        result.dependencies.push(...deps);
+      }
+      return result;
+    } else {
+      return call(options);
+    }
+  };
+}