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/d3-quadtree/package.json

@@ -0,0 +1,49 @@
+{
+  "name": "d3-quadtree",
+  "version": "3.0.1",
+  "description": "Two-dimensional recursive spatial subdivision.",
+  "homepage": "https://d3js.org/d3-quadtree/",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/d3/d3-quadtree.git"
+  },
+  "keywords": [
+    "d3",
+    "d3-module",
+    "quadtree"
+  ],
+  "license": "ISC",
+  "author": {
+    "name": "Mike Bostock",
+    "url": "http://bost.ocks.org/mike"
+  },
+  "type": "module",
+  "files": [
+    "dist/**/*.js",
+    "src/**/*.js"
+  ],
+  "module": "src/index.js",
+  "main": "src/index.js",
+  "jsdelivr": "dist/d3-quadtree.min.js",
+  "unpkg": "dist/d3-quadtree.min.js",
+  "exports": {
+    "umd": "./dist/d3-quadtree.min.js",
+    "default": "./src/index.js"
+  },
+  "sideEffects": false,
+  "devDependencies": {
+    "d3-array": "1 - 2",
+    "eslint": "7",
+    "mocha": "8",
+    "rollup": "2",
+    "rollup-plugin-terser": "7"
+  },
+  "scripts": {
+    "test": "mocha 'test/**/*-test.js' && eslint src test",
+    "prepublishOnly": "rm -rf dist && yarn test && rollup -c",
+    "postpublish": "git push && git push --tags && cd ../d3.github.com && git pull && cp ../${npm_package_name}/dist/${npm_package_name}.js ${npm_package_name}.v${npm_package_version%%.*}.js && cp ../${npm_package_name}/dist/${npm_package_name}.min.js ${npm_package_name}.v${npm_package_version%%.*}.min.js && git add ${npm_package_name}.v${npm_package_version%%.*}.js ${npm_package_name}.v${npm_package_version%%.*}.min.js && git commit -m \"${npm_package_name} ${npm_package_version}\" && git push && cd -"
+  },
+  "engines": {
+    "node": ">=12"
+  }
+}