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/delayed-stream/lib/delayed_stream.js

@@ -0,0 +1,107 @@
+var Stream = require('stream').Stream;
+var util = require('util');
+
+module.exports = DelayedStream;
+function DelayedStream() {
+  this.source = null;
+  this.dataSize = 0;
+  this.maxDataSize = 1024 * 1024;
+  this.pauseStream = true;
+
+  this._maxDataSizeExceeded = false;
+  this._released = false;
+  this._bufferedEvents = [];
+}
+util.inherits(DelayedStream, Stream);
+
+DelayedStream.create = function(source, options) {
+  var delayedStream = new this();
+
+  options = options || {};
+  for (var option in options) {
+    delayedStream[option] = options[option];
+  }
+
+  delayedStream.source = source;
+
+  var realEmit = source.emit;
+  source.emit = function() {
+    delayedStream._handleEmit(arguments);
+    return realEmit.apply(source, arguments);
+  };
+
+  source.on('error', function() {});
+  if (delayedStream.pauseStream) {
+    source.pause();
+  }
+
+  return delayedStream;
+};
+
+Object.defineProperty(DelayedStream.prototype, 'readable', {
+  configurable: true,
+  enumerable: true,
+  get: function() {
+    return this.source.readable;
+  }
+});
+
+DelayedStream.prototype.setEncoding = function() {
+  return this.source.setEncoding.apply(this.source, arguments);
+};
+
+DelayedStream.prototype.resume = function() {
+  if (!this._released) {
+    this.release();
+  }
+
+  this.source.resume();
+};
+
+DelayedStream.prototype.pause = function() {
+  this.source.pause();
+};
+
+DelayedStream.prototype.release = function() {
+  this._released = true;
+
+  this._bufferedEvents.forEach(function(args) {
+    this.emit.apply(this, args);
+  }.bind(this));
+  this._bufferedEvents = [];
+};
+
+DelayedStream.prototype.pipe = function() {
+  var r = Stream.prototype.pipe.apply(this, arguments);
+  this.resume();
+  return r;
+};
+
+DelayedStream.prototype._handleEmit = function(args) {
+  if (this._released) {
+    this.emit.apply(this, args);
+    return;
+  }
+
+  if (args[0] === 'data') {
+    this.dataSize += args[1].length;
+    this._checkIfMaxDataSizeExceeded();
+  }
+
+  this._bufferedEvents.push(args);
+};
+
+DelayedStream.prototype._checkIfMaxDataSizeExceeded = function() {
+  if (this._maxDataSizeExceeded) {
+    return;
+  }
+
+  if (this.dataSize <= this.maxDataSize) {
+    return;
+  }
+
+  this._maxDataSizeExceeded = true;
+  var message =
+    'DelayedStream#maxDataSize of ' + this.maxDataSize + ' bytes exceeded.'
+  this.emit('error', new Error(message));
+};