feat: add SQLite migration and DB init with WAL mode

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

LORAWEB_NEU/backend/daemon/src/db.rs

@@ -0,0 +1,99 @@
+// backend/daemon/src/db.rs
+use sqlx::SqlitePool;
+use chrono::Utc;
+use uuid::Uuid;
+
+pub async fn init_db(pool: &SqlitePool) -> Result<(), sqlx::Error> {
+    sqlx::query("PRAGMA journal_mode=WAL").execute(pool).await?;
+    sqlx::query("PRAGMA busy_timeout=5000").execute(pool).await?;
+
+    let migration = include_str!("../../../database/migrations/001_initial.sql");
+    for statement in migration.split(';') {
+        let stmt = statement.trim();
+        if !stmt.is_empty() {
+            sqlx::query(stmt).execute(pool).await?;
+        }
+    }
+    Ok(())
+}
+
+pub async fn register_topic(pool: &SqlitePool, dev_eui: &str) -> Result<(), sqlx::Error> {
+    let now = Utc::now().to_rfc3339();
+    let id = Uuid::new_v4().to_string();
+    sqlx::query(
+        "INSERT OR IGNORE INTO topics (id, topic, approved, alarm_status, alarm_threshold_hours, created_at) \
+         VALUES (?, ?, 0, 'unknown', 0.0, ?)"
+    )
+    .bind(&id)
+    .bind(dev_eui)
+    .bind(&now)
+    .execute(pool)
+    .await?;
+    Ok(())
+}
+
+pub async fn update_last_seen(pool: &SqlitePool, dev_eui: &str, timestamp: &str) -> Result<(), sqlx::Error> {
+    sqlx::query("UPDATE topics SET last_seen = ? WHERE topic = ?")
+        .bind(timestamp)
+        .bind(dev_eui)
+        .execute(pool)
+        .await?;
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use sqlx::SqlitePool;
+
+    #[tokio::test]
+    async fn test_init_db_creates_tables() {
+        let pool = SqlitePool::connect("sqlite::memory:").await.unwrap();
+        init_db(&pool).await.unwrap();
+
+        let topics: (i64,) = sqlx::query_as("SELECT COUNT(*) FROM topics")
+            .fetch_one(&pool).await.unwrap();
+        assert_eq!(topics.0, 0);
+
+        let sensors: (i64,) = sqlx::query_as("SELECT COUNT(*) FROM sensors")
+            .fetch_one(&pool).await.unwrap();
+        assert_eq!(sensors.0, 0);
+
+        let users: (i64,) = sqlx::query_as("SELECT COUNT(*) FROM users")
+            .fetch_one(&pool).await.unwrap();
+        assert_eq!(users.0, 0);
+    }
+
+    #[tokio::test]
+    async fn test_init_db_is_idempotent() {
+        let pool = SqlitePool::connect("sqlite::memory:").await.unwrap();
+        init_db(&pool).await.unwrap();
+        init_db(&pool).await.unwrap(); // should not error
+    }
+
+    #[tokio::test]
+    async fn test_register_topic() {
+        let pool = SqlitePool::connect("sqlite::memory:").await.unwrap();
+        init_db(&pool).await.unwrap();
+
+        register_topic(&pool, "abcdef1234567890").await.unwrap();
+
+        let count: (i64,) = sqlx::query_as("SELECT COUNT(*) FROM topics WHERE topic = ?")
+            .bind("abcdef1234567890")
+            .fetch_one(&pool).await.unwrap();
+        assert_eq!(count.0, 1);
+    }
+
+    #[tokio::test]
+    async fn test_register_topic_idempotent() {
+        let pool = SqlitePool::connect("sqlite::memory:").await.unwrap();
+        init_db(&pool).await.unwrap();
+
+        register_topic(&pool, "abcdef1234567890").await.unwrap();
+        register_topic(&pool, "abcdef1234567890").await.unwrap();
+
+        let count: (i64,) = sqlx::query_as("SELECT COUNT(*) FROM topics")
+            .fetch_one(&pool).await.unwrap();
+        assert_eq!(count.0, 1);
+    }
+}

LORAWEB_NEU/database/migrations/001_initial.sql

@@ -0,0 +1,33 @@
+-- database/migrations/001_initial.sql
+
+CREATE TABLE IF NOT EXISTS topics (
+    id TEXT PRIMARY KEY,
+    topic TEXT UNIQUE NOT NULL,
+    approved INTEGER NOT NULL DEFAULT 0,
+    last_seen TEXT,
+    alarm_status TEXT NOT NULL DEFAULT 'unknown',
+    alarm_threshold_hours REAL NOT NULL DEFAULT 0.0,
+    created_at TEXT NOT NULL
+);
+
+CREATE TABLE IF NOT EXISTS sensors (
+    id TEXT PRIMARY KEY,
+    name TEXT NOT NULL,
+    description TEXT NOT NULL DEFAULT '',
+    location TEXT NOT NULL DEFAULT '',
+    sensor_type TEXT NOT NULL DEFAULT '',
+    active INTEGER NOT NULL DEFAULT 1,
+    topic_id TEXT REFERENCES topics(id),
+    display_config TEXT NOT NULL DEFAULT '{}',
+    created_at TEXT NOT NULL
+);
+
+CREATE TABLE IF NOT EXISTS users (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    username TEXT UNIQUE NOT NULL,
+    password_hash TEXT NOT NULL,
+    role TEXT NOT NULL DEFAULT 'user',
+    totp_secret TEXT,
+    totp_enabled INTEGER NOT NULL DEFAULT 0,
+    created_at TEXT NOT NULL
+);