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/runed/dist/utilities/use-throttle/use-throttle.svelte.js

@@ -0,0 +1,82 @@
+import { untrack } from "svelte";
+export function useThrottle(callback, interval = 250) {
+    let lastCall = 0;
+    let timeout = $state();
+    let resolve = null;
+    let reject = null;
+    let promise = null;
+    function reset() {
+        timeout = undefined;
+        promise = null;
+        resolve = null;
+        reject = null;
+    }
+    function throttled(...args) {
+        return untrack(() => {
+            const now = Date.now();
+            const intervalValue = typeof interval === "function" ? interval() : interval;
+            const nextAllowedTime = lastCall + intervalValue;
+            if (!promise) {
+                promise = new Promise((res, rej) => {
+                    resolve = res;
+                    reject = rej;
+                });
+            }
+            if (now < nextAllowedTime) {
+                if (!timeout) {
+                    timeout = setTimeout(async () => {
+                        try {
+                            const result = await callback.apply(this, args);
+                            resolve?.(result);
+                        }
+                        catch (error) {
+                            reject?.(error);
+                        }
+                        finally {
+                            clearTimeout(timeout);
+                            reset();
+                            lastCall = Date.now();
+                        }
+                    }, nextAllowedTime - now);
+                }
+                return promise;
+            }
+            if (timeout) {
+                clearTimeout(timeout);
+                timeout = undefined;
+            }
+            lastCall = now;
+            try {
+                const result = callback.apply(this, args);
+                resolve?.(result);
+            }
+            catch (error) {
+                reject?.(error);
+            }
+            finally {
+                reset();
+            }
+            return promise;
+        });
+    }
+    throttled.cancel = async () => {
+        if (timeout) {
+            if (timeout === undefined) {
+                // Wait one event loop to see if something triggered the throttled function
+                await new Promise((resolve) => setTimeout(resolve, 0));
+                if (timeout === undefined)
+                    return;
+            }
+            clearTimeout(timeout);
+            reject?.("Cancelled");
+            reset();
+        }
+    };
+    Object.defineProperty(throttled, "pending", {
+        enumerable: true,
+        get() {
+            return !!timeout;
+        },
+    });
+    return throttled;
+}