feat: add iOS support and harden receipt scanning

app/ios/ScanReceipts/Models/User.swift

@@ -0,0 +1,88 @@
+import Foundation
+
+/// Mirrors the `user` object returned by `GET /api/auth/session` and
+/// `POST /api/auth/login` (src/app/api/auth/session/route.ts). Field names
+/// are already camelCase in the JSON, so no custom `CodingKeys`/key-decoding
+/// strategy is needed anywhere in this file.
+///
+/// Date fields are kept as raw ISO-8601 strings (with fractional seconds,
+/// e.g. `2026-08-20T19:37:42.307Z` from `Date.toISOString()`) rather than
+/// `Date`, because `JSONDecoder`'s built-in `.iso8601` strategy does NOT
+/// parse fractional seconds and would silently fail to decode every
+/// timestamp this backend sends. Use `ISO8601.parse(_:)` (Support/ISO8601.swift)
+/// where you actually need a `Date`.
+struct User: Decodable, Identifiable, Equatable {
+    let id: String
+    let email: String?
+    let name: String?
+    let plan: String
+    let isGuest: Bool
+    let isPro: Bool
+    let cancelAtPeriodEnd: Bool
+    let emailVerified: Bool
+    let launchBonus: Bool
+    let freeScanAllowance: Int
+    let scanCount: Int
+    let company: String?
+    let useCase: String?
+    let expiresAt: String?
+    let createdAt: String?
+    let onboardingCompletedAt: String?
+
+    /// True once onboarding (company/use-case/etc.) has been completed — the
+    /// dashboard's post-signup wizard on web, skippable but tracked the same
+    /// way in the app.
+    var hasCompletedOnboarding: Bool { onboardingCompletedAt != nil }
+
+    /// Reconstructs the UUID `newId("usr")` originally minted this account's
+    /// `id` from (see `src/lib/auth/tokens.ts` on the backend: `"usr_" +
+    /// randomUUID().replace(/-/g, "")` — i.e. `id` IS a UUID with its dashes
+    /// stripped and a prefix glued on, nothing more). Re-inserting the
+    /// dashes recovers that exact UUID losslessly — no extra network call,
+    /// no server-issued token to fetch and cache.
+    ///
+    /// Passed as StoreKit's `appAccountToken` on purchase (see
+    /// `StoreKitPurchaseService.purchase`) so `POST /api/webhooks/apple`
+    /// (`src/lib/billing/appleIAP.ts` → `userIdFromAppAccountToken`) can
+    /// reverse the same transformation server-side and know which account a
+    /// given App Store transaction belongs to — that's the ONLY thing this
+    /// value is for; it carries no other meaning to Apple.
+    var appleAccountToken: UUID? {
+        guard id.hasPrefix("usr_") else { return nil }
+        let hex = String(id.dropFirst(4))
+        guard hex.count == 32, hex.allSatisfy(\.isHexDigit) else { return nil }
+        let parts = [
+            hex.prefix(8),
+            hex.dropFirst(8).prefix(4),
+            hex.dropFirst(12).prefix(4),
+            hex.dropFirst(16).prefix(4),
+            hex.dropFirst(20),
+        ]
+        return UUID(uuidString: parts.joined(separator: "-"))
+    }
+}
+
+/// The minimal user echo returned inline by `POST /api/auth/login` and
+/// `/signup` (a subset of `User` — those endpoints don't run the extra
+/// queries `/api/auth/session` does). Kept separate so a login response
+/// decodes without requiring fields it doesn't send.
+struct LoginResponse: Decodable {
+    let status: String
+    let user: LoginUser
+    /// Present only when the request carried `X-Client: ios` — see
+    /// src/app/api/auth/login/route.ts. Absent for a browser-style caller.
+    let token: String?
+    let expiresAt: String?
+}
+
+struct LoginUser: Decodable {
+    let id: String
+    let email: String?
+    let name: String?
+    let plan: String
+    let onboardingCompletedAt: String?
+}
+
+struct SessionResponse: Decodable {
+    let user: User?
+}