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/internal/roving-focus-group.js

@@ -0,0 +1,97 @@
+import { box } from "svelte-toolbelt";
+import { getElemDirection } from "./locale.js";
+import { getDirectionalKeys } from "./get-directional-keys.js";
+import { kbd } from "./kbd.js";
+import { BROWSER } from "esm-env";
+import { isHTMLElement } from "./is.js";
+export class RovingFocusGroup {
+    #opts;
+    #currentTabStopId = box(null);
+    constructor(opts) {
+        this.#opts = opts;
+    }
+    getCandidateNodes() {
+        if (!BROWSER || !this.#opts.rootNode.current)
+            return [];
+        if (this.#opts.candidateSelector) {
+            const candidates = Array.from(this.#opts.rootNode.current.querySelectorAll(this.#opts.candidateSelector));
+            return candidates;
+        }
+        else if (this.#opts.candidateAttr) {
+            const candidates = Array.from(this.#opts.rootNode.current.querySelectorAll(`[${this.#opts.candidateAttr}]:not([data-disabled])`));
+            return candidates;
+        }
+        return [];
+    }
+    focusFirstCandidate() {
+        const items = this.getCandidateNodes();
+        if (!items.length)
+            return;
+        items[0]?.focus();
+    }
+    handleKeydown(node, e, both = false) {
+        const rootNode = this.#opts.rootNode.current;
+        if (!rootNode || !node)
+            return;
+        const items = this.getCandidateNodes();
+        if (!items.length)
+            return;
+        const currentIndex = items.indexOf(node);
+        const dir = getElemDirection(rootNode);
+        const { nextKey, prevKey } = getDirectionalKeys(dir, this.#opts.orientation.current);
+        const loop = this.#opts.loop.current;
+        const keyToIndex = {
+            [nextKey]: currentIndex + 1,
+            [prevKey]: currentIndex - 1,
+            [kbd.HOME]: 0,
+            [kbd.END]: items.length - 1,
+        };
+        if (both) {
+            const altNextKey = nextKey === kbd.ARROW_DOWN ? kbd.ARROW_RIGHT : kbd.ARROW_DOWN;
+            const altPrevKey = prevKey === kbd.ARROW_UP ? kbd.ARROW_LEFT : kbd.ARROW_UP;
+            keyToIndex[altNextKey] = currentIndex + 1;
+            keyToIndex[altPrevKey] = currentIndex - 1;
+        }
+        let itemIndex = keyToIndex[e.key];
+        if (itemIndex === undefined)
+            return;
+        e.preventDefault();
+        if (itemIndex < 0 && loop) {
+            itemIndex = items.length - 1;
+        }
+        else if (itemIndex === items.length && loop) {
+            itemIndex = 0;
+        }
+        const itemToFocus = items[itemIndex];
+        if (!itemToFocus)
+            return;
+        itemToFocus.focus();
+        this.#currentTabStopId.current = itemToFocus.id;
+        this.#opts.onCandidateFocus?.(itemToFocus);
+        return itemToFocus;
+    }
+    getTabIndex(node) {
+        const items = this.getCandidateNodes();
+        const anyActive = this.#currentTabStopId.current !== null;
+        if (node && !anyActive && items[0] === node) {
+            this.#currentTabStopId.current = node.id;
+            return 0;
+        }
+        else if (node?.id === this.#currentTabStopId.current) {
+            return 0;
+        }
+        return -1;
+    }
+    setCurrentTabStopId(id) {
+        this.#currentTabStopId.current = id;
+    }
+    focusCurrentTabStop() {
+        const currentTabStopId = this.#currentTabStopId.current;
+        if (!currentTabStopId)
+            return;
+        const currentTabStop = this.#opts.rootNode.current?.querySelector(`#${currentTabStopId}`);
+        if (!currentTabStop || !isHTMLElement(currentTabStop))
+            return;
+        currentTabStop.focus();
+    }
+}