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/dist/mascot/LICENSE-eggs.txt

@@ -0,0 +1,20 @@
+Eggs
+By Onocentaur
+https://onocentaur.itch.io
+March 2021
+
+Description 
+350+ pixel art eggs for your next virtual pet/match 3/farming/holiday themed game.
+
+This pack contains:
+	⁃	Over 350 16x16px eggs.
+	⁃	32 egg designs, 11 color variants.
+	⁃	2 different cracking animations for each egg.
+	⁃	Spritesheets for each color variant and cracking pattern.
+	⁃	Transparent PNGs.
+	⁃	Template files so you can color your own eggs.
+	⁃	Bonus: Letter & Number eggs.
+	⁃	Bonus: Incubator assets (nesting box and toggle-able lamp).
+	⁃	Bonus: 12 Animal assets.  
+
+Free to use for personal & professional projects.  Attribution appreciated.  If you use these assets in your project, let me know!  I look forward to seeing what you make.

web/dist/mascot/LICENSE.txt

@@ -0,0 +1,5 @@
+
+CC0 1.0 Universal (CC0 1.0) Public Domain Dedication 
+
+The person who associated a work with this deed has dedicated the work to the public domain by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
+You can copy, modify, distribute and perform the work, even for commercial purposes, all without asking permission.