feat: Settings page, DELETE traces endpoint, Anthropic SDK, dashboard bug fixes

- Add /dashboard/settings with SDK connection details, data stats, purge
- Add DELETE /api/traces/[id] with cascade deletion
- Add Anthropic integration (wrap_anthropic) for Python SDK
- Fix missing root duration (totalDuration -> durationMs mapping)
- Fix truncated JSON in decision tree nodes (extract readable labels)
- Fix hardcoded 128K maxTokens in token gauge (model-aware context windows)
- Enable Settings nav item in sidebar

apps/web/src/app/api/settings/purge/route.ts

@@ -0,0 +1,21 @@
+import { NextResponse } from "next/server";
+import { prisma } from "@/lib/prisma";
+
+export async function POST() {
+  try {
+    await prisma.$transaction([
+      prisma.event.deleteMany(),
+      prisma.decisionPoint.deleteMany(),
+      prisma.span.deleteMany(),
+      prisma.trace.deleteMany(),
+    ]);
+
+    return NextResponse.json({ success: true }, { status: 200 });
+  } catch (error) {
+    console.error("Error purging data:", error);
+    return NextResponse.json(
+      { error: "Internal server error" },
+      { status: 500 }
+    );
+  }
+}

apps/web/src/app/api/settings/stats/route.ts

@@ -0,0 +1,25 @@
+import { NextResponse } from "next/server";
+import { prisma } from "@/lib/prisma";
+
+export async function GET() {
+  try {
+    const [totalTraces, totalSpans, totalDecisions, totalEvents] =
+      await Promise.all([
+        prisma.trace.count(),
+        prisma.span.count(),
+        prisma.decisionPoint.count(),
+        prisma.event.count(),
+      ]);
+
+    return NextResponse.json(
+      { totalTraces, totalSpans, totalDecisions, totalEvents },
+      { status: 200 }
+    );
+  } catch (error) {
+    console.error("Error fetching stats:", error);
+    return NextResponse.json(
+      { error: "Internal server error" },
+      { status: 500 }
+    );
+  }
+}

apps/web/src/app/api/traces/[id]/route.ts

@@ -1,10 +1,26 @@
-import { NextResponse } from "next/server";
+import { NextRequest, NextResponse } from "next/server";
 import { prisma } from "@/lib/prisma";
 
+type RouteParams = { params: Promise<{ id: string }> };
+
+function extractActionLabel(value: unknown): string {
+  if (typeof value === "string") return value;
+  if (value && typeof value === "object" && !Array.isArray(value)) {
+    const obj = value as Record<string, unknown>;
+    if (typeof obj.name === "string") return obj.name;
+    if (typeof obj.action === "string") return obj.action;
+    if (typeof obj.tool === "string") return obj.tool;
+    for (const v of Object.values(obj)) {
+      if (typeof v === "string") return v;
+    }
+  }
+  return JSON.stringify(value);
+}
+
 // GET /api/traces/[id] — Get single trace with all relations
 export async function GET(
-  _request: Request,
-  { params }: { params: Promise<{ id: string }> }
+  _request: NextRequest,
+  { params }: RouteParams
 ) {
   try {
     const { id } = await params;
@@ -41,11 +57,13 @@ export async function GET(
     // Transform data to match frontend expectations
     const transformedTrace = {
       ...trace,
+      durationMs: trace.totalDuration,
+      costUsd: trace.totalCost,
       decisionPoints: trace.decisionPoints.map((dp) => ({
         id: dp.id,
         type: dp.type,
-        chosenAction: typeof dp.chosen === "string" ? dp.chosen : JSON.stringify(dp.chosen),
-        alternatives: dp.alternatives.map((alt) => (typeof alt === "string" ? alt : JSON.stringify(alt))),
+        chosenAction: extractActionLabel(dp.chosen),
+        alternatives: dp.alternatives.map((alt) => extractActionLabel(alt)),
         reasoning: dp.reasoning,
         contextSnapshot: dp.contextSnapshot as Record<string, unknown> | null,
         confidence: null, // Not in schema, default to null
@@ -81,3 +99,35 @@ export async function GET(
     return NextResponse.json({ error: "Internal server error" }, { status: 500 });
   }
 }
+
+// DELETE /api/traces/[id] — Delete a trace and all related data (cascade)
+export async function DELETE(
+  _request: NextRequest,
+  { params }: RouteParams
+) {
+  try {
+    const { id } = await params;
+
+    if (!id || typeof id !== "string") {
+      return NextResponse.json({ error: "Invalid trace ID" }, { status: 400 });
+    }
+
+    const trace = await prisma.trace.findUnique({
+      where: { id },
+      select: { id: true },
+    });
+
+    if (!trace) {
+      return NextResponse.json({ error: "Trace not found" }, { status: 404 });
+    }
+
+    await prisma.trace.delete({
+      where: { id },
+    });
+
+    return NextResponse.json({ success: true, deleted: id }, { status: 200 });
+  } catch (error) {
+    console.error("Error deleting trace:", error);
+    return NextResponse.json({ error: "Internal server error" }, { status: 500 });
+  }
+}