ai: rich-output blocks via lazy-fetched typed-fence protocol

Assistant replies can now emit typed fenced blocks that render as
@crema/*-ui components inline at their position in the reply.

- message-body.tsx: segmented rendering — alternating prose chunks and
  block dispatch (was: all blocks appended at end). Renderers for kpi,
  table, chart-bar/-line/-donut/-spark, code, diff, flowchart, orgchart,
  steps, checklist, welcome, hint, plus the legacy card kinds.
- block-schemas.ts: single source of truth — BLOCK_INDEX (one-line
  purpose per kind, always in prompt) + SCHEMAS (full JSON shape +
  example, fetched on demand).
- admin-tools.ts: new get_block_schema(kind) tool the model calls once
  per kind per thread to fetch the exact schema. Keeps the always-on
  prompt small (~110 tokens vs ~400 inline).
- assistant.tsx: replaces the inline schema dump with the generated
  thin index.
- ai.tsx: empty-state preview button injects a synthetic assistant
  message exercising every block, for renderer/theme smoke-testing.
- console.css + ai.tsx: shrink ATLAS headline so it doesn't slip under
  the composer with the added preview button.
- tsconfig.json + app.css: wire lib-data-ui, lib-code-ui, lib-diagram-ui,
  lib-onboarding-ui as siblings.

Adding a new block kind = add the lib paths, add a renderer case, add
a schema entry. No prompt edits required.

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

app/lib/admin-tools.ts

@@ -15,6 +15,8 @@ import {
   suspendTenant,
   type Tenant,
 } from "~/lib/arcadia/tenants"
+import { searchDocs } from "~/lib/docs-search"
+import { BLOCK_INDEX, getBlockSchema } from "~/lib/block-schemas"
 
 export type ToolCall = {
   name: string
@@ -221,6 +223,71 @@ const TOOLS: ToolDef[] = [
       return summarize(updated)
     },
   },
+  {
+    name: "search_docs",
+    description:
+      "Search the arcadia-app documentation (architecture, API surface, deploy/setup guides) for passages relevant to a question. Use this for conceptual or procedural questions where the live API tools won't help — e.g. 'how does multi-tenant isolation work', 'how do I deploy to production', 'what is the modular monolith pattern'. Returns up to `limit` ranked passages with title, sourcePath, and excerpt. Cite results by sourcePath in your reply.",
+    parameters: {
+      type: "object",
+      properties: {
+        query: {
+          type: "string",
+          description:
+            "Lexical search query. Use specific terms from the docs (endpoint names, schema fields, concept names) — paraphrase poorly.",
+        },
+        limit: {
+          type: "integer",
+          description: "Max passages to return. Default 5, cap 10.",
+          minimum: 1,
+          maximum: 10,
+        },
+      },
+      required: ["query"],
+      additionalProperties: false,
+    },
+    isWrite: false,
+    run: async (args) => {
+      const query = typeof args.query === "string" ? args.query.trim() : ""
+      if (!query) throw new Error("search_docs requires a non-empty { query }")
+      const limit = Math.min(
+        10,
+        Math.max(1, typeof args.limit === "number" ? args.limit : 5),
+      )
+      const hits = await searchDocs(query, limit)
+      return { query, count: hits.length, hits }
+    },
+  },
+  {
+    name: "get_block_schema",
+    description: `Fetch the full JSON schema + example for a rich-output block kind so you can emit it correctly in your reply. Call this the first time in a thread that you intend to render a particular kind. Available kinds: ${Object.entries(
+      BLOCK_INDEX,
+    )
+      .map(([k, v]) => `${k} (${v})`)
+      .join(", ")}.`,
+    parameters: {
+      type: "object",
+      properties: {
+        kind: {
+          type: "string",
+          description: "The block kind to fetch the schema for.",
+          enum: Object.keys(BLOCK_INDEX),
+        },
+      },
+      required: ["kind"],
+      additionalProperties: false,
+    },
+    isWrite: false,
+    run: async (args) => {
+      const kind = typeof args.kind === "string" ? args.kind : ""
+      const schema = getBlockSchema(kind)
+      if (!schema) {
+        return {
+          error: `Unknown block kind "${kind}". Available: ${Object.keys(BLOCK_INDEX).join(", ")}.`,
+        }
+      }
+      return { kind, schema }
+    },
+  },
 ]
 
 interface AuditEntry {