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/routes/assistant.tsx

@@ -233,13 +233,13 @@ const mockAdapter = new MockLLM({
     },
     {
       matches: (req) =>
-        /(take me to|open|navigate|go to).*(resources|library|settings|activity|assistant|overview|home)/i.test(
+        /(take me to|open|navigate|go to).*(tenants|users|library|settings|activity|assistant|overview|home)/i.test(
           req.messages.at(-1)?.content ?? "",
         ),
       response: [
         "On it.\n\n",
         "```action\n",
-        "navigate /resources\n",
+        "navigate /tenants\n",
         "```\n",
       ],
     },
@@ -411,7 +411,7 @@ export default function AssistantRoute() {
     status.kind === "live" ? model || status.models[0] : "mock"
 
   return (
-    <AppShell title="Assistant">
+    <AppShell>
       <LLMProvider adapter={adapter} model={activeModel}>
         <AssistantSurface
           key={`${activeThreadId}-${compactNonce}`}