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/bits-ui/dist/bits/avatar/avatar.svelte.js

@@ -0,0 +1,105 @@
+import { DOMContext, attachRef, } from "svelte-toolbelt";
+import { Context, watch } from "runed";
+import { createBitsAttrs } from "../../internal/attrs.js";
+const avatarAttrs = createBitsAttrs({
+    component: "avatar",
+    parts: ["root", "image", "fallback"],
+});
+const AvatarRootContext = new Context("Avatar.Root");
+export class AvatarRootState {
+    static create(opts) {
+        return AvatarRootContext.set(new AvatarRootState(opts));
+    }
+    opts;
+    domContext;
+    attachment;
+    constructor(opts) {
+        this.opts = opts;
+        this.domContext = new DOMContext(this.opts.ref);
+        this.loadImage = this.loadImage.bind(this);
+        this.attachment = attachRef(this.opts.ref);
+    }
+    loadImage(src, crossorigin, referrerPolicy) {
+        if (this.opts.loadingStatus.current === "loaded")
+            return;
+        let imageTimerId;
+        const image = new Image();
+        image.src = src;
+        if (crossorigin !== undefined)
+            image.crossOrigin = crossorigin;
+        if (referrerPolicy)
+            image.referrerPolicy = referrerPolicy;
+        this.opts.loadingStatus.current = "loading";
+        image.onload = () => {
+            imageTimerId = this.domContext.setTimeout(() => {
+                this.opts.loadingStatus.current = "loaded";
+            }, this.opts.delayMs.current);
+        };
+        image.onerror = () => {
+            this.opts.loadingStatus.current = "error";
+        };
+        return () => {
+            if (!imageTimerId)
+                return;
+            this.domContext.clearTimeout(imageTimerId);
+        };
+    }
+    props = $derived.by(() => ({
+        id: this.opts.id.current,
+        [avatarAttrs.root]: "",
+        "data-status": this.opts.loadingStatus.current,
+        ...this.attachment,
+    }));
+}
+export class AvatarImageState {
+    static create(opts) {
+        return new AvatarImageState(opts, AvatarRootContext.get());
+    }
+    opts;
+    root;
+    attachment;
+    constructor(opts, root) {
+        this.opts = opts;
+        this.root = root;
+        this.attachment = attachRef(this.opts.ref);
+        watch.pre([() => this.opts.src.current, () => this.opts.crossOrigin.current], ([src, crossOrigin]) => {
+            if (!src) {
+                this.root.opts.loadingStatus.current = "error";
+                return;
+            }
+            this.root.loadImage(src, crossOrigin, this.opts.referrerPolicy.current);
+        });
+    }
+    props = $derived.by(() => ({
+        id: this.opts.id.current,
+        style: {
+            display: this.root.opts.loadingStatus.current === "loaded" ? "block" : "none",
+        },
+        "data-status": this.root.opts.loadingStatus.current,
+        [avatarAttrs.image]: "",
+        src: this.opts.src.current,
+        crossorigin: this.opts.crossOrigin.current,
+        referrerpolicy: this.opts.referrerPolicy.current,
+        ...this.attachment,
+    }));
+}
+export class AvatarFallbackState {
+    static create(opts) {
+        return new AvatarFallbackState(opts, AvatarRootContext.get());
+    }
+    opts;
+    root;
+    attachment;
+    constructor(opts, root) {
+        this.opts = opts;
+        this.root = root;
+        this.attachment = attachRef(this.opts.ref);
+    }
+    style = $derived.by(() => this.root.opts.loadingStatus.current === "loaded" ? { display: "none" } : undefined);
+    props = $derived.by(() => ({
+        style: this.style,
+        "data-status": this.root.opts.loadingStatus.current,
+        [avatarAttrs.fallback]: "",
+        ...this.attachment,
+    }));
+}