Add full application: receipt scanning, auth, billing, and account deletion

Brings the working codebase (Next.js app, auth system, Stripe billing,
Docker/deploy config, tests, docs) into version control on top of the
placeholder initial commit, and adds account self-deletion (Danger Zone
in Settings, password + typed-email confirmation, cascading DB cleanup,
Stripe cancellation) per GDPR right-to-erasure.

Excludes local build caches, node_modules, and internal agent scratch
files; .gitignore hardened to keep those out going forward.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/app/api/auth/session/route.ts

@@ -0,0 +1,45 @@
+import { NextResponse } from "next/server";
+import { getCurrentUser } from "@/lib/auth/session";
+import { FREE_SCAN_LIMIT, LAUNCH_BONUS_SCANS } from "@/lib/limits";
+import { isProActive } from "@/lib/billing/access";
+
+export const runtime = "nodejs";
+export const dynamic = "force-dynamic";
+
+/** Who am I? Returns `{ user: null }` when signed out — never an error. */
+export async function GET() {
+  try {
+    const user = await getCurrentUser();
+    if (!user) return NextResponse.json({ user: null });
+
+    const isPro = isProActive(user);
+
+    return NextResponse.json({
+      user: {
+        id: user.id,
+        email: user.email,
+        name: user.name,
+        plan: user.plan,
+        isGuest: user.isGuest,
+        isPro,
+        cancelAtPeriodEnd: Boolean(user.cancelAtPeriodEnd),
+        emailVerified: Boolean(user.emailVerifiedAt),
+        launchBonus: Boolean(user.launchBonus),
+        freeScanAllowance: user.launchBonus ? LAUNCH_BONUS_SCANS : FREE_SCAN_LIMIT,
+        scanCount: Number(user.scanCount ?? 0),
+        company: user.company ?? null,
+        useCase: user.useCase ?? null,
+        monthlyVolume: user.monthlyVolume ?? null,
+        exportFormat: user.exportFormat ?? null,
+        mainPainPoint: user.mainPainPoint ?? null,
+        referralSource: user.referralSource ?? null,
+        expiresAt: user.expiresAt?.toISOString() ?? null,
+        createdAt: user.createdAt?.toISOString() ?? null,
+        onboardingCompletedAt: user.onboardingCompletedAt?.toISOString() ?? null,
+      },
+    });
+  } catch {
+    // Database down: treat as signed out rather than breaking the shell.
+    return NextResponse.json({ user: null });
+  }
+}