feat: Nostr-native data models + initial schema

models/db.rs: User keyed by pubkey_hash/nostr_pubkey/username (pubkey_hash and
seed_fingerprint peppered at rest); Wallet, Session (platform=extension|web|nostr),
UserKey, GrinSlatepack, AuditLog. Dropped all telegram/discord/social-identity
columns and every tip/social/swap struct (swaps land as their own feature unit).

migrations/20260622000001_initial_schema: consolidated clean schema; enum types;
UNIQUE on identity columns; FK ON DELETE (CASCADE/SET NULL) for self-service
erasure; indexes on every lookup column. PostgreSQL 13+.

src/lib.rs

@@ -11,3 +11,4 @@
 pub mod api;
 pub mod config;
 pub mod error;
+pub mod models;

src/models/db.rs

@@ -0,0 +1,246 @@
+//! Database entity models. These map directly to tables and are used with sqlx.
+//!
+//! Identity is Nostr-native: a user is keyed by `pubkey_hash` (the wallet's
+//! identity pubkey), an optional `nostr_pubkey`, and an optional reserved
+//! `username`. `pubkey_hash` and `seed_fingerprint` are stored HMAC-peppered at
+//! rest (the pepper lives in config); the values here are already peppered.
+
+use chrono::{DateTime, Utc};
+use ipnetwork::IpNetwork;
+use serde::{Deserialize, Serialize};
+use sqlx::FromRow;
+use uuid::Uuid;
+
+// ── Enums (mapped to PostgreSQL enum types) ─────────────────────────────────
+
+/// Supported cryptocurrency assets.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize, sqlx::Type)]
+#[sqlx(type_name = "asset_type", rename_all = "lowercase")]
+pub enum AssetType {
+    Btc,
+    Ltc,
+    Xmr,
+    Wow,
+    Grin,
+}
+
+impl AssetType {
+    pub fn as_str(&self) -> &'static str {
+        match self {
+            AssetType::Btc => "btc",
+            AssetType::Ltc => "ltc",
+            AssetType::Xmr => "xmr",
+            AssetType::Wow => "wow",
+            AssetType::Grin => "grin",
+        }
+    }
+}
+
+impl std::fmt::Display for AssetType {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.as_str())
+    }
+}
+
+/// Grin slatepack relay status.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize, sqlx::Type)]
+#[sqlx(type_name = "slatepack_status", rename_all = "snake_case")]
+pub enum SlatepackStatus {
+    PendingRecipient,
+    PendingSender,
+    Finalized,
+    Expired,
+    Cancelled,
+}
+
+/// Audit log action types.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize, sqlx::Type)]
+#[sqlx(type_name = "audit_action", rename_all = "snake_case")]
+pub enum AuditAction {
+    UserCreated,
+    UserLogin,
+    WalletCreated,
+    WalletRegistered,
+    TxBroadcast,
+    SessionCreated,
+    SessionRevoked,
+}
+
+// ── Entities (field order matches column order) ─────────────────────────────
+
+/// A user account. Identity is the wallet's key material, not a platform login.
+#[derive(Debug, Clone, FromRow, Serialize)]
+pub struct User {
+    pub id: Uuid,
+    /// Reserved `@handle` (backs NIP-05). Unique, optional.
+    pub username: Option<String>,
+    /// Peppered hash of the wallet identity pubkey. Unique, optional.
+    pub pubkey_hash: Option<String>,
+    /// The user's Nostr public key (hex). Unique, optional.
+    pub nostr_pubkey: Option<String>,
+    /// Approximate wallet creation time, to bound chain scans.
+    pub wallet_birthday: Option<DateTime<Utc>>,
+    /// Peppered seed fingerprint, for restore lookup. Unique, optional.
+    pub seed_fingerprint: Option<String>,
+    /// Monero scan start height (skip pre-birthday blocks).
+    pub xmr_start_height: Option<i64>,
+    /// Wownero scan start height.
+    pub wow_start_height: Option<i64>,
+    pub created_at: DateTime<Utc>,
+    pub updated_at: DateTime<Utc>,
+    pub last_seen_at: Option<DateTime<Utc>>,
+}
+
+/// A wallet associated with a user.
+///
+/// Non-custodial: we store the public address and (for XMR/WOW) the view key
+/// for balance scanning. We NEVER store a spend key or seed.
+#[derive(Debug, Clone, FromRow, Serialize)]
+pub struct Wallet {
+    pub id: Uuid,
+    pub user_id: Uuid,
+    pub asset: AssetType,
+    pub address: String,
+    /// View key (XMR/WOW only) for balance scanning.
+    pub view_key: Option<String>,
+    /// HD derivation index (BTC/LTC).
+    pub derivation_index: Option<i32>,
+    pub registered_with_node: bool,
+    pub registration_error: Option<String>,
+    pub label: Option<String>,
+    pub created_at: DateTime<Utc>,
+    pub updated_at: DateTime<Utc>,
+}
+
+/// A session backing a JWT refresh token.
+#[derive(Debug, Clone, FromRow, Serialize)]
+pub struct Session {
+    pub id: Uuid,
+    pub user_id: Uuid,
+    /// Peppered hash of the refresh token (never the token itself).
+    pub refresh_token_hash: String,
+    /// Client kind: `extension`, `web`, or `nostr`.
+    pub platform: String,
+    pub device_info: Option<String>,
+    pub ip_address: Option<IpNetwork>,
+    pub created_at: DateTime<Utc>,
+    pub expires_at: DateTime<Utc>,
+    pub revoked_at: Option<DateTime<Utc>>,
+    pub last_used_at: DateTime<Utc>,
+}
+
+/// A user's per-asset public key, so others can send to them.
+#[derive(Debug, Clone, FromRow, Serialize)]
+pub struct UserKey {
+    pub id: Uuid,
+    pub user_id: Uuid,
+    pub asset: AssetType,
+    /// The public key (format depends on asset).
+    pub public_key: String,
+    /// Public spend key (XMR/WOW).
+    pub public_spend_key: Option<String>,
+    /// `primary` or `backup`.
+    pub key_type: String,
+    pub created_at: DateTime<Utc>,
+    pub updated_at: DateTime<Utc>,
+}
+
+/// A Grin slatepack relayed between two parties for an interactive transaction.
+#[derive(Debug, Clone, FromRow, Serialize)]
+pub struct GrinSlatepack {
+    pub id: Uuid,
+    pub slate_id: String,
+    pub sender_user_id: Uuid,
+    /// Recipient user (if registered on this backend).
+    pub recipient_user_id: Option<Uuid>,
+    /// Recipient slatepack address (if not registered here).
+    pub recipient_address: Option<String>,
+    pub slatepack_content: String,
+    pub amount_nanogrin: i64,
+    pub status: SlatepackStatus,
+    pub response_slatepack: Option<String>,
+    pub created_at: DateTime<Utc>,
+    pub updated_at: DateTime<Utc>,
+    pub expires_at: DateTime<Utc>,
+    pub finalized_at: Option<DateTime<Utc>>,
+    pub tx_hash: Option<String>,
+}
+
+/// Audit log entry for security-relevant actions.
+#[derive(Debug, Clone, FromRow, Serialize)]
+pub struct AuditLog {
+    pub id: Uuid,
+    pub user_id: Option<Uuid>,
+    pub action: AuditAction,
+    pub resource_type: Option<String>,
+    pub resource_id: Option<Uuid>,
+    pub details: Option<serde_json::Value>,
+    pub ip_address: Option<IpNetwork>,
+    pub user_agent: Option<String>,
+    pub created_at: DateTime<Utc>,
+}
+
+// ── Input structs (no auto-generated fields) ────────────────────────────────
+
+/// Input for creating a new user. Peppered values are supplied by the db layer.
+#[derive(Debug, Clone)]
+pub struct NewUser {
+    pub username: Option<String>,
+    pub pubkey_hash: Option<String>,
+    pub nostr_pubkey: Option<String>,
+    pub wallet_birthday: Option<DateTime<Utc>>,
+    pub seed_fingerprint: Option<String>,
+    pub xmr_start_height: Option<i64>,
+    pub wow_start_height: Option<i64>,
+}
+
+#[derive(Debug, Clone)]
+pub struct NewWallet {
+    pub user_id: Uuid,
+    pub asset: AssetType,
+    pub address: String,
+    pub view_key: Option<String>,
+    pub derivation_index: Option<i32>,
+    pub label: Option<String>,
+}
+
+#[derive(Debug, Clone)]
+pub struct NewSession {
+    pub user_id: Uuid,
+    pub refresh_token_hash: String,
+    pub platform: String,
+    pub device_info: Option<String>,
+    pub ip_address: Option<IpNetwork>,
+    pub expires_at: DateTime<Utc>,
+}
+
+#[derive(Debug, Clone)]
+pub struct NewUserKey {
+    pub user_id: Uuid,
+    pub asset: AssetType,
+    pub public_key: String,
+    pub public_spend_key: Option<String>,
+    pub key_type: String,
+}
+
+#[derive(Debug, Clone)]
+pub struct NewGrinSlatepack {
+    pub slate_id: String,
+    pub sender_user_id: Uuid,
+    pub recipient_user_id: Option<Uuid>,
+    pub recipient_address: Option<String>,
+    pub slatepack_content: String,
+    pub amount_nanogrin: i64,
+    pub expires_at: DateTime<Utc>,
+}
+
+#[derive(Debug, Clone)]
+pub struct NewAuditLog {
+    pub user_id: Option<Uuid>,
+    pub action: AuditAction,
+    pub resource_type: Option<String>,
+    pub resource_id: Option<Uuid>,
+    pub details: Option<serde_json::Value>,
+    pub ip_address: Option<IpNetwork>,
+    pub user_agent: Option<String>,
+}

src/models/mod.rs

@@ -0,0 +1,5 @@
+//! Data models: database entities (sqlx) and shared types.
+//!
+//! Request/response DTOs are added alongside the handlers that use them.
+
+pub mod db;