feat(web): add windowed Settings app, separate from initial Config screen

The taskbar's gear icon reopened the full-page "Connect to Oikos" screen
even once already connected. Split that: Config.svelte stays as the
first-run/unconfigured screen; a new Settings app (windowed, like Tasks or
Operations) now handles in-session changes, with a section list (Connection,
Appearance) built to grow — future settings are one more entry, not a new
screen.

- pages/Settings.svelte: Connection (server URL/token/Authentik, reusing
  config.ts + oidc.ts) and Appearance (Terracotta/Carbon picker) sections.
- apps.ts: registered as a normal desktop app.
- Taskbar's gear button now opens the Settings window; removed the
  onOpenConnection prop threaded through App -> Desktop -> Taskbar, since
  Settings' "Forget saved connection" (clear config + reload) replaces it.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

web/src/lib/apps.ts

@@ -15,12 +15,14 @@ import Ops from '../pages/Ops.svelte'
 import Signals from '../pages/Signals.svelte'
 import Knowledge from '../pages/Knowledge.svelte'
 import Learning from '../pages/Learning.svelte'
+import Settings from '../pages/Settings.svelte'
 import ListTodoIcon from '@lucide/svelte/icons/list-todo'
 import DatabaseIcon from '@lucide/svelte/icons/database'
 import ShieldCheckIcon from '@lucide/svelte/icons/shield-check'
 import SirenIcon from '@lucide/svelte/icons/siren'
 import SearchIcon from '@lucide/svelte/icons/search'
 import TrendingUpIcon from '@lucide/svelte/icons/trending-up'
+import SettingsIcon from '@lucide/svelte/icons/settings'
 
 export interface AppDef {
   id: string
@@ -99,6 +101,16 @@ export const APPS: AppDef[] = [
     height: 600,
     minWidth: 440,
     minHeight: 340
+  },
+  {
+    id: 'settings',
+    title: 'Settings',
+    icon: SettingsIcon,
+    component: Settings,
+    width: 640,
+    height: 480,
+    minWidth: 480,
+    minHeight: 360
   }
 ]
 

web/src/lib/components/desktop-shell/Desktop.svelte

@@ -21,8 +21,6 @@
   import Undo2Icon from '@lucide/svelte/icons/undo-2'
   import Redo2Icon from '@lucide/svelte/icons/redo-2'
 
-  let { onOpenConnection }: { onOpenConnection: () => void } = $props()
-
   // Clicking the bare desktop (not an icon, not a window) blurs the focused
   // window — the familiar "click empty desktop to deselect" affordance.
   function onSurfaceClick(e: MouseEvent) {
@@ -104,7 +102,7 @@
     <WindowLayer />
   </div>
 
-  <Taskbar {onOpenConnection} />
+  <Taskbar />
 </div>
 
 {#if menuPos}

web/src/lib/components/desktop-shell/Taskbar.svelte

@@ -6,7 +6,7 @@
   // to the old MinimizedWindowsBar, which only ever showed minimized windows
   // and gave no way to see/switch between windows that were merely
   // unfocused), plus a system tray for theme/connection/version.
-  import { wm, wmState, toggleShowDesktop } from '$lib/stores/windows'
+  import { wm, wmState, toggleShowDesktop, openAppWindow } from '$lib/stores/windows'
   import { appById, appIdFromWindowId } from '$lib/apps'
   import { summary } from '$lib/stores/context'
   import { truncateMiddle } from '$lib/utils'
@@ -19,8 +19,6 @@
   import LayoutGridIcon from '@lucide/svelte/icons/layout-grid'
   import XIcon from '@lucide/svelte/icons/x'
 
-  let { onOpenConnection }: { onOpenConnection: () => void } = $props()
-
   const SESSION_PREFIX = 'session:'
 
   const buttons = $derived(
@@ -121,8 +119,8 @@
     <button
       type="button"
       class="flex items-center justify-center rounded-md p-1.5 text-muted-foreground hover:bg-muted hover:text-foreground"
-      onclick={onOpenConnection}
-      title="Server connection settings"
+      onclick={() => openAppWindow('settings')}
+      title="Settings"
     >
       <SettingsIcon class="size-4" />
     </button>