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/@lucide/svelte/dist/icons/droplets.svelte

@@ -0,0 +1,23 @@
+<!--
+@lucide/svelte v1.28.0 - ISC
+
+This source code is licensed under the ISC license.
+See the LICENSE file in the root directory of this source tree.
+-->
+
+
+<script lang="ts">import Icon from '../Icon.svelte';
+let props = $props();
+const iconNode = [["path", { "d": "M7 16.3c2.2 0 4-1.83 4-4.05 0-1.16-.57-2.26-1.71-3.19S7.29 6.75 7 5.3c-.29 1.45-1.14 2.84-2.29 3.76S3 11.1 3 12.25c0 2.22 1.8 4.05 4 4.05z" }], ["path", { "d": "M12.56 6.6A10.97 10.97 0 0 0 14 3.02c.5 2.5 2 4.9 4 6.5s3 3.5 3 5.5a6.98 6.98 0 0 1-11.91 4.97" }]];
+</script>
+
+<!--
+@component
+
+Lucide SVG icon component, renders SVG Element with children.
+
+@preview ![img](data:image/svg+xml;base64,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) - https://lucide.dev/icons/droplets
+@see https://lucide.dev/guide/packages/lucide-svelte - Documentation
+-->
+
+<Icon name="droplets" {...props} iconNode={iconNode} />