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/postcss/lib/fromJSON.js

@@ -0,0 +1,107 @@
+'use strict'
+
+let AtRule = require('./at-rule')
+let Comment = require('./comment')
+let Declaration = require('./declaration')
+let Input = require('./input')
+let PreviousMap = require('./previous-map')
+let Root = require('./root')
+let Rule = require('./rule')
+
+function hydrateInputs(json, inputs) {
+  if (!json.inputs) return inputs
+  return json.inputs.map(input => {
+    let inputHydrated = { ...input, __proto__: Input.prototype }
+    if (inputHydrated.map) {
+      inputHydrated.map = {
+        ...inputHydrated.map,
+        __proto__: PreviousMap.prototype
+      }
+    }
+    return inputHydrated
+  })
+}
+
+function constructNode(json, inputs, children) {
+  let defaults = { ...json }
+  delete defaults.inputs
+  delete defaults.nodes
+  if (defaults.source) {
+    let { inputId, ...source } = defaults.source
+    defaults.source = source
+    if (inputId != null) {
+      defaults.source.input = inputs[inputId]
+    }
+  }
+
+  let node
+  if (defaults.type === 'root') {
+    node = new Root(defaults)
+  } else if (defaults.type === 'decl') {
+    node = new Declaration(defaults)
+  } else if (defaults.type === 'rule') {
+    node = new Rule(defaults)
+  } else if (defaults.type === 'comment') {
+    node = new Comment(defaults)
+  } else if (defaults.type === 'atrule') {
+    node = new AtRule(defaults)
+  } else {
+    throw new Error('Unknown node type: ' + json.type)
+  }
+
+  // Rehydrated children are attached after construction. Passing them
+  // through the container constructor would re-run insertion spacing
+  // normalization and overwrite each child's own `raws.before`.
+  if (children) {
+    node.nodes = children
+    for (let child of children) child.parent = node
+  }
+
+  return node
+}
+
+function fromJSON(json, inputs) {
+  if (Array.isArray(json)) return json.map(n => fromJSON(n))
+
+  // An explicit stack instead of recursive calls to survive deeply
+  // nested trees. Children are rehydrated before their parent node
+  // is constructed.
+  let result
+  let stack = [
+    { childIndex: 0, children: [], inputs: hydrateInputs(json, inputs), json }
+  ]
+
+  while (stack.length > 0) {
+    let frame = stack[stack.length - 1]
+    let jsonNodes = frame.json.nodes
+
+    if (jsonNodes && frame.childIndex < jsonNodes.length) {
+      let childJson = jsonNodes[frame.childIndex]
+      frame.childIndex += 1
+      stack.push({
+        childIndex: 0,
+        children: [],
+        inputs: hydrateInputs(childJson, frame.inputs),
+        json: childJson
+      })
+      continue
+    }
+
+    stack.pop()
+    let node = constructNode(
+      frame.json,
+      frame.inputs,
+      jsonNodes ? frame.children : undefined
+    )
+    if (stack.length > 0) {
+      stack[stack.length - 1].children.push(node)
+    } else {
+      result = node
+    }
+  }
+
+  return result
+}
+
+module.exports = fromJSON
+fromJSON.default = fromJSON