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/Icon.svelte

@@ -0,0 +1,26 @@
+<script lang="ts">import defaultAttributes from './defaultAttributes.js';
+import { hasA11yProp } from './utils/hasA11yProp.js';
+import { getLucideContext } from './context.js';
+const globalProps = getLucideContext() ?? {};
+const { name, color = globalProps.color ?? 'currentColor', size = globalProps.size ?? 24, strokeWidth = globalProps.strokeWidth ?? 2, absoluteStrokeWidth = globalProps.absoluteStrokeWidth ?? false, iconNode = [], children, ...props } = $props();
+const calculatedStrokeWidth = $derived(absoluteStrokeWidth ? (Number(strokeWidth) * 24) / Number(size) : strokeWidth);
+</script>
+
+<svg
+  {...defaultAttributes}
+  {...!children && !hasA11yProp(props) && { 'aria-hidden': 'true' }}
+  {...props}
+  width={size}
+  height={size}
+  stroke={color}
+  stroke-width={calculatedStrokeWidth}
+  class={['lucide-icon lucide', globalProps.class, name && `lucide-${name}`, props.class]}
+>
+  {#each iconNode as [tag, attrs]}
+    <svelte:element
+      this={tag as string}
+      {...attrs}
+    />
+  {/each}
+  {@render children?.()}
+</svg>