feat(settings): add Blocks tab — 12-block decision schema reference

Read-only display of BLOCK_CONFIG from block_writer.py with CREAC role
and JWM functional-purpose annotations per block (sourced from
docs/block-schema.md).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web-ui/src/app/settings/page.tsx

@@ -1,13 +1,14 @@
 "use client";
 
 import Link from "next/link";
-import { Server, Wrench, Plug, Building2 } from "lucide-react";
+import { Server, Wrench, Plug, Building2, Layers } from "lucide-react";
 import { AppShell } from "@/components/app-shell";
 import { Tabs, TabsContent, TabsList, TabsTrigger } from "@/components/ui/tabs";
 import { PaperclipTab } from "./_components/paperclip-tab";
 import { EnvironmentTab } from "./_components/environment-tab";
 import { ToolsTab } from "./_components/tools-tab";
 import { RegistrationsTab } from "./_components/registrations-tab";
+import { BlocksTab } from "./_components/blocks-tab";
 
 export default function SettingsPage() {
   return (
@@ -43,6 +44,10 @@ export default function SettingsPage() {
               <Wrench className="w-4 h-4" data-icon="inline-start" />
               Tools
             </TabsTrigger>
+            <TabsTrigger value="blocks">
+              <Layers className="w-4 h-4" data-icon="inline-start" />
+              Blocks
+            </TabsTrigger>
             <TabsTrigger value="registrations">
               <Plug className="w-4 h-4" data-icon="inline-start" />
               Registrations
@@ -52,6 +57,7 @@ export default function SettingsPage() {
           <TabsContent value="paperclip"><PaperclipTab /></TabsContent>
           <TabsContent value="environment"><EnvironmentTab /></TabsContent>
           <TabsContent value="tools"><ToolsTab /></TabsContent>
+          <TabsContent value="blocks"><BlocksTab /></TabsContent>
           <TabsContent value="registrations"><RegistrationsTab /></TabsContent>
         </Tabs>
       </section>