Wire AI assistant to arcadia: domain primer, tool calling, admin context

Make /ai and /assistant operate as the platform admin's assistant
against arcadia-app's API:

- Add `arcadia-knowledge.ts` — domain primer (multi-tenant Phoenix
  backend, tenant lifecycle, platform_admins identity, etc.) baked into
  every system prompt.
- Add `admin-tools.ts` — curated tool registry exposing `list_tenants`
  and `get_tenant`, callable via OpenAI-native function calling. Tools
  hit arcadia through `useArcadiaClient()` and inherit the operator's
  JWT + tenant header. `runLLMToolCalls()` returns `tool` role messages
  ready to push back into history.
- Add `admin-context.ts` — runtime registry pages publish to so the
  assistant can answer factual questions about live UI state without
  scraping the DOM. Tenants page registers its summary on mount.
- Replace generic Vibespace personas (Atlas/Forge/Inkwell/Pilot/Cursor)
  with arcadia-flavoured ones: Operator, Auditor, Triage, Analyst,
  UI Operator. Auto-migrate stored agents from the legacy set.
- /assistant: build admin preface (role + primer + persona + ctx) and
  pass it as the `useChat` system at construction. Pass `tools` on every
  `send()`. Auto-loop reads `toolCalls` off the streaming assistant
  message and uses `continueChat()` to push tool results.
- /ai: same wiring (this is the canonical admin chat surface; the user
  prefers its look).
- MessageBody renders tool-result cards (role: "tool") and a "Called X"
  pill on assistant messages with toolCalls. Strips Qwen-style
  `<tool_call>` XML from prose when the tags were converted to
  structured calls.
- Extend ThreadMessage with the `tool` role + tool-call metadata so
  conversations round-trip through localStorage.
- Tenants page: row actions get `data-action="tenant-<slug>-{suspend,
  activate,deactivate}"` (via lib-table-ui's new dataAction prop);
  registers tenant summary into admin-context.

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

app/lib/threads.ts

@@ -4,10 +4,16 @@
 import { useEffect, useSyncExternalStore } from "react"
 
 export type ThreadMessage = {
-  role: "user" | "assistant"
+  role: "user" | "assistant" | "tool"
   content: string
   /** Persona that authored this assistant message (omitted for user msgs). */
   agentId?: string
+  /** Native tool calls attached to an assistant message. */
+  toolCalls?: { id: string; name: string; arguments: string }[]
+  /** Tool role only — id of the matching assistant tool_call. */
+  toolCallId?: string
+  /** Tool role only — function name. */
+  name?: string
 }
 
 export type Thread = {