Wails v3 desktop app: scaffold, shell features, token mgmt, auto-update, CI

Problem: the Oikos control room was browser-only — no native desktop
experience (system tray, notifications, keychain-persisted auth).

Change: add a Wails v3 thin-shell desktop app at cmd/desktop/ that embeds
the existing SPA in a webview. The Go side is ~380 lines — no bundled
server, no Postgres connection. It reads auth from the OS keychain,
injects it into the SPA on load, and the SPA talks HTTPS to the homelab
same as a browser.

Phase 1.0 — Scaffold + window:
  - Embed web/dist/ into the Wails binary
  - Inject window.__OIKOS_CONFIG__ with keychain-stored apiUrl + token
  - 1400×900 window, min 1024×700
  - System tray: Open/Quit, click toggles window

Phase 1.1 — Native shell:
  - Poll /api/v1/dashboard/summary every 30s; osascript notification
    when approvals or critical signals increase
  - Save/restore window position to ~/.config/oikos/window.json
  - EnableAutoStart/DisableAutoStart — macOS LaunchAgent plist

Phase 1.2 — Token management:
  - Config.svelte calls window.wails.Call.ByName('SaveConfig') after
    successful connection — persists to OS keychain
  - ConfigService binds SaveConfig, ClearConfig, EnableAutoStart,
    DisableAutoStart to the Wails runtime

Phase 1.3 — Auto-update:
  - Poll Gitea releases API every 6h, compare semver, show dialog
  - 'Check for Updates' tray menu item triggers immediate poll

Phase 1.4 — Distribution:
  - macOS entitlements.plist: network client + keychain access
  - .gitea/workflows/desktop.yml: CI builds macOS arm64 + Linux amd64
    on 'desktop-*' / 'v*' tags, attaches artifacts to release
  - Makefile: desktop (build), desktop-package (build + zip/tar.gz)
  - CONTRIBUTING.md: documented desktop app + commands

Risk: low. Wails v3 alpha API may shift; the Go glue is ~380 lines and
trivially portable. The desktop app is additive — zero changes to the
existing server or SPA logic. No config mutation, no infrastructure
impact.

Verification: go build, go vet, go mod tidy all pass.

go.mod

@@ -14,6 +14,8 @@ require (
 	github.com/modelcontextprotocol/go-sdk v1.6.1
 	github.com/oapi-codegen/runtime v1.4.2
 	github.com/openai/openai-go v1.12.0
+	github.com/wailsapp/wails/v3 v3.0.0-alpha2.117
+	github.com/zalando/go-keyring v0.2.8
 	golang.org/x/crypto v0.53.0
 	golang.org/x/sync v0.21.0
 	golang.org/x/sys v0.46.0
@@ -25,6 +27,7 @@ require (
 	cloud.google.com/go/auth/oauth2adapt v0.2.8 // indirect
 	cloud.google.com/go/compute/metadata v0.9.0 // indirect
 	cloud.google.com/go/iam v1.1.11 // indirect
+	github.com/adrg/xdg v0.5.3 // indirect
 	github.com/apapsch/go-jsonmerge/v2 v2.0.0 // indirect
 	github.com/aws/aws-sdk-go-v2 v1.27.2 // indirect
 	github.com/aws/aws-sdk-go-v2/config v1.27.18 // indirect
@@ -40,12 +43,16 @@ require (
 	github.com/aws/aws-sdk-go-v2/service/sts v1.28.12 // indirect
 	github.com/aws/smithy-go v1.20.2 // indirect
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
+	github.com/coder/websocket v1.8.14 // indirect
+	github.com/danieljoos/wincred v1.2.3 // indirect
 	github.com/felixge/httpsnoop v1.0.4 // indirect
 	github.com/go-logr/logr v1.4.3 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
+	github.com/go-ole/go-ole v1.3.0 // indirect
 	github.com/go-openapi/jsonpointer v0.22.5 // indirect
 	github.com/go-openapi/swag/jsonname v0.25.5 // indirect
 	github.com/go-resty/resty/v2 v2.13.1 // indirect
+	github.com/godbus/dbus/v5 v5.2.2 // indirect
 	github.com/gofrs/flock v0.8.1 // indirect
 	github.com/google/s2a-go v0.1.9 // indirect
 	github.com/googleapis/enterprise-certificate-proxy v0.3.11 // indirect
@@ -54,6 +61,9 @@ require (
 	github.com/jackc/pgpassfile v1.0.0 // indirect
 	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
 	github.com/jackc/puddle/v2 v2.2.2 // indirect
+	github.com/jchv/go-winloader v0.0.0-20250406163304-c1995be93bd1 // indirect
+	github.com/mattn/go-colorable v0.1.14 // indirect
+	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/oasdiff/yaml v0.1.0 // indirect
 	github.com/oasdiff/yaml3 v0.0.13 // indirect
 	github.com/oracle/oci-go-sdk/v65 v65.95.2 // indirect