oikos-web: extract the client stack from dtoro/oikos

Phase 1 of the hexagonal-architecture plan (dtoro/oikos
plans/2026-08-15-hexagonal-architecture.md). Moves the delivery stack
for the control-room UI into its own repo with its own pipeline:

- web/ — Svelte 5 SPA, verbatim (vendor/ included)
- desktop/ — Wails v3 wrapper, updateURL repointed to
  dtoro/oikos-web releases
- compose/ — Dockerfile + Caddyfile, verbatim (the /wails/* 404 and
  asset no-fallback quirks are load-bearing)
- docker-compose.yml — single web service, same 8091:80 publish,
  mem/cpu limits, and restart policy as the oikos stack's web service
- scripts/deploy.sh — mirrors oikos deploy essentials: CI-green gate,
  TOCTOU guard, version-tagged oikos-web:v$VERSION, prune to 3
- cmd/webhook + scripts/install-webhook.sh — standalone push-to-deploy
  receiver on :9798 (env-only secrets, no Infisical dependency)
- CI: the web job from oikos's ci.yml + the desktop build/release
  workflow, path-adjusted

Own VERSION (0.33.0) with the same bump-on-main rule; starts above
oikos's 0.32.x so the desktop updater sees an upgrade.

scripts/oikos-web-deploy-webhook.plist

@@ -0,0 +1,38 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+    <key>Label</key>
+    <string>oikos-web-deploy-webhook</string>
+    <key>ProgramArguments</key>
+    <array>
+        <string>/Users/dtoro/Projects/oikos-web/webhook</string>
+    </array>
+    <key>EnvironmentVariables</key>
+    <dict>
+        <key>WEBHOOK_LISTEN</key>
+        <string>:9798</string>
+        <key>WEBHOOK_REPO_DIR</key>
+        <string>/Users/dtoro/Projects/oikos-web</string>
+        <!-- Rendered by install-webhook.sh at install time (same values as
+             the oikos stack: HMAC from Infisical webhook_hmac-secret, Gitea
+             PAT for the CI gate, Oikos API token for failure events). -->
+        <key>WEBHOOK_HMAC_SECRET</key>
+        <string>SET_AT_INSTALL</string>
+        <key>GITEA_URL</key>
+        <string>https://git.hubris.network</string>
+        <key>GITEA_TOKEN</key>
+        <string>SET_AT_INSTALL</string>
+        <key>OIKOS_API_TOKEN</key>
+        <string>SET_AT_INSTALL</string>
+    </dict>
+    <key>RunAtLoad</key>
+    <true/>
+    <key>KeepAlive</key>
+    <true/>
+    <key>StandardOutPath</key>
+    <string>/tmp/oikos-web-deploy-webhook.log</string>
+    <key>StandardErrorPath</key>
+    <string>/tmp/oikos-web-deploy-webhook.log</string>
+</dict>
+</plist>