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/graceful-fs/legacy-streams.js

@@ -0,0 +1,118 @@
+var Stream = require('stream').Stream
+
+module.exports = legacy
+
+function legacy (fs) {
+  return {
+    ReadStream: ReadStream,
+    WriteStream: WriteStream
+  }
+
+  function ReadStream (path, options) {
+    if (!(this instanceof ReadStream)) return new ReadStream(path, options);
+
+    Stream.call(this);
+
+    var self = this;
+
+    this.path = path;
+    this.fd = null;
+    this.readable = true;
+    this.paused = false;
+
+    this.flags = 'r';
+    this.mode = 438; /*=0666*/
+    this.bufferSize = 64 * 1024;
+
+    options = options || {};
+
+    // Mixin options into this
+    var keys = Object.keys(options);
+    for (var index = 0, length = keys.length; index < length; index++) {
+      var key = keys[index];
+      this[key] = options[key];
+    }
+
+    if (this.encoding) this.setEncoding(this.encoding);
+
+    if (this.start !== undefined) {
+      if ('number' !== typeof this.start) {
+        throw TypeError('start must be a Number');
+      }
+      if (this.end === undefined) {
+        this.end = Infinity;
+      } else if ('number' !== typeof this.end) {
+        throw TypeError('end must be a Number');
+      }
+
+      if (this.start > this.end) {
+        throw new Error('start must be <= end');
+      }
+
+      this.pos = this.start;
+    }
+
+    if (this.fd !== null) {
+      process.nextTick(function() {
+        self._read();
+      });
+      return;
+    }
+
+    fs.open(this.path, this.flags, this.mode, function (err, fd) {
+      if (err) {
+        self.emit('error', err);
+        self.readable = false;
+        return;
+      }
+
+      self.fd = fd;
+      self.emit('open', fd);
+      self._read();
+    })
+  }
+
+  function WriteStream (path, options) {
+    if (!(this instanceof WriteStream)) return new WriteStream(path, options);
+
+    Stream.call(this);
+
+    this.path = path;
+    this.fd = null;
+    this.writable = true;
+
+    this.flags = 'w';
+    this.encoding = 'binary';
+    this.mode = 438; /*=0666*/
+    this.bytesWritten = 0;
+
+    options = options || {};
+
+    // Mixin options into this
+    var keys = Object.keys(options);
+    for (var index = 0, length = keys.length; index < length; index++) {
+      var key = keys[index];
+      this[key] = options[key];
+    }
+
+    if (this.start !== undefined) {
+      if ('number' !== typeof this.start) {
+        throw TypeError('start must be a Number');
+      }
+      if (this.start < 0) {
+        throw new Error('start must be >= zero');
+      }
+
+      this.pos = this.start;
+    }
+
+    this.busy = false;
+    this._queue = [];
+
+    if (this.fd === null) {
+      this._open = fs.open;
+      this._queue.push([this._open, this.path, this.flags, this.mode, undefined]);
+      this.flush();
+    }
+  }
+}