admin: completeness + UI consistency pass

Arcadia wiring:
- home: real Overview dashboard (tenants/users/audit/health probe) replacing the inherited Vibespace welcome tiles; skeleton loaders, refresh button, registers admin context
- profile: split into Account (synced via getUser/updateUser of session user) and local Preferences; updateSessionUser keeps the appbar in sync after edits
- session: drop unused signIn mock, add updateSessionUser, refresh tests
- profile schema: drop redundant Profile.name/email (session is the source of truth)
- routes: delete orphaned resources route + lib

Auth flows that previously 404'd:
- /signup, /login/forgot, /login/reset, /login/2fa wired via @crema/arcadia-auth-ui
- shared AuthShell + AuthBrand wrapper

Assistant tools (admin-tools.ts):
- +10 tools: deactivate_tenant, set_user_status, delete_user, list_memberships, list_roles, revoke_api_key, create_user, update_user, assign_role, remove_role
- list_memberships gains user_id filter for "tenants this user belongs to" queries
- search_kb / read_chunk: new token resolution (window override → VITE_ARCADIA_SEARCH_TOKEN service token → operator session JWT → "dev"); on 401/403 emit a tailored hint based on which token was used

UI consistency:
- new PageHeader component
- AppShell.title was unrendered — dropped; first-child padding on #main-content keeps the floating actions pill from colliding with header content
- removed dead "Sign in required" fallback cards from 14 routes (AppShell already redirects)
- stripped p-6 from outer wrappers across 14 routes (was double-padding under AppShell's own p-6)
- migrated home + tenants to PageHeader

arcadia-search ergonomics:
- scripts/mint-search-token.mjs + `npm run mint:search-token` mints HS512 JWT with required tenant_id claim, upserts VITE_ARCADIA_SEARCH_TOKEN into .env.local
- README/.env document the new VITE_ARCADIA_SEARCH_URL / VITE_ARCADIA_SEARCH_TOKEN knobs
- .env.local now gitignored

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/components/layout/page-header.tsx

@@ -0,0 +1,36 @@
+import { type ReactNode } from "react"
+
+interface PageHeaderProps {
+  title: ReactNode
+  description?: ReactNode
+  /** Inline indicators after the title (badges, status pills). */
+  badges?: ReactNode
+  /** Toolbar rendered below the title row — primary actions go here. */
+  actions?: ReactNode
+}
+
+// Right-side space for the appbar's floating actions pill is reserved by
+// the AppShell's first-child padding rule, not here — keep this layout
+// concerned only with title/description/actions composition.
+
+export function PageHeader({
+  title,
+  description,
+  badges,
+  actions,
+}: PageHeaderProps) {
+  return (
+    <header className="flex flex-col gap-2">
+      <div className="flex flex-wrap items-center gap-3">
+        <h1 className="text-2xl font-semibold tracking-tight">{title}</h1>
+        {badges}
+      </div>
+      {description ? (
+        <p className="max-w-3xl text-sm text-muted-foreground">{description}</p>
+      ) : null}
+      {actions ? (
+        <div className="mt-1 flex flex-wrap items-center gap-2">{actions}</div>
+      ) : null}
+    </header>
+  )
+}