feat(settings): implement Tools tab with detail drawer

Replaces stub ToolsTab with a grouped-by-module grid of clickable tool cards.
Adds ToolDetailDrawer (Sheet) showing name, description, module, source_location,
and params_schema for the selected tool.

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

web-ui/src/app/settings/_components/tool-detail-drawer.tsx

@@ -0,0 +1,65 @@
+"use client";
+
+import {
+  Sheet,
+  SheetContent,
+  SheetHeader,
+  SheetTitle,
+  SheetDescription,
+} from "@/components/ui/sheet";
+import { Badge } from "@/components/ui/badge";
+import type { McpTool } from "@/lib/api/settings";
+
+type Props = {
+  tool: McpTool | null;
+  open: boolean;
+  onOpenChange: (o: boolean) => void;
+};
+
+export function ToolDetailDrawer({ tool, open, onOpenChange }: Props) {
+  return (
+    <Sheet open={open} onOpenChange={onOpenChange}>
+      <SheetContent side="left" className="sm:max-w-xl overflow-y-auto">
+        {tool && (
+          <>
+            <SheetHeader>
+              <SheetTitle dir="ltr" className="font-mono text-navy">
+                {tool.name}
+              </SheetTitle>
+              <SheetDescription>{tool.description || "—"}</SheetDescription>
+            </SheetHeader>
+            <div className="space-y-4 mt-4 px-4 pb-6">
+              <div>
+                <div className="text-[0.72rem] text-ink-muted uppercase mb-1">
+                  Module
+                </div>
+                <Badge variant="outline" className="font-mono" dir="ltr">
+                  {tool.module}
+                </Badge>
+              </div>
+              <div>
+                <div className="text-[0.72rem] text-ink-muted uppercase mb-1">
+                  Source
+                </div>
+                <code dir="ltr" className="text-xs text-ink break-all">
+                  {tool.source_location || "—"}
+                </code>
+              </div>
+              <div>
+                <div className="text-[0.72rem] text-ink-muted uppercase mb-1">
+                  Parameters Schema
+                </div>
+                <pre
+                  dir="ltr"
+                  className="text-xs bg-rule-soft/40 border border-rule rounded-md p-3 overflow-x-auto"
+                >
+                  {JSON.stringify(tool.params_schema, null, 2)}
+                </pre>
+              </div>
+            </div>
+          </>
+        )}
+      </SheetContent>
+    </Sheet>
+  );
+}