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/json-buffer/index.js

@@ -0,0 +1,58 @@
+//TODO: handle reviver/dehydrate function like normal
+//and handle indentation, like normal.
+//if anyone needs this... please send pull request.
+
+exports.stringify = function stringify (o) {
+  if('undefined' == typeof o) return o
+
+  if(o && Buffer.isBuffer(o))
+    return JSON.stringify(':base64:' + o.toString('base64'))
+
+  if(o && o.toJSON)
+    o =  o.toJSON()
+
+  if(o && 'object' === typeof o) {
+    var s = ''
+    var array = Array.isArray(o)
+    s = array ? '[' : '{'
+    var first = true
+
+    for(var k in o) {
+      var ignore = 'function' == typeof o[k] || (!array && 'undefined' === typeof o[k])
+      if(Object.hasOwnProperty.call(o, k) && !ignore) {
+        if(!first)
+          s += ','
+        first = false
+        if (array) {
+          if(o[k] == undefined)
+            s += 'null'
+          else
+            s += stringify(o[k])
+        } else if (o[k] !== void(0)) {
+          s += stringify(k) + ':' + stringify(o[k])
+        }
+      }
+    }
+
+    s += array ? ']' : '}'
+
+    return s
+  } else if ('string' === typeof o) {
+    return JSON.stringify(/^:/.test(o) ? ':' + o : o)
+  } else if ('undefined' === typeof o) {
+    return 'null';
+  } else
+    return JSON.stringify(o)
+}
+
+exports.parse = function (s) {
+  return JSON.parse(s, function (key, value) {
+    if('string' === typeof value) {
+      if(/^:base64:/.test(value))
+        return Buffer.from(value.substring(8), 'base64')
+      else
+        return /^:/.test(value) ? value.substring(1) : value 
+    }
+    return value
+  })
+}