Add PostgreSQL database persistence

- Add connect_machines, connect_sessions, connect_session_events, connect_support_codes tables
- Implement db module with connection pooling (sqlx)
- Add machine persistence across server restarts
- Add audit logging for session/viewer events
- Support codes now persisted to database

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

server/src/db/support_codes.rs

@@ -0,0 +1,141 @@
+//! Support code database operations
+
+use chrono::{DateTime, Utc};
+use serde::{Deserialize, Serialize};
+use sqlx::PgPool;
+use uuid::Uuid;
+
+/// Support code record from database
+#[derive(Debug, Clone, Serialize, Deserialize, sqlx::FromRow)]
+pub struct DbSupportCode {
+    pub id: Uuid,
+    pub code: String,
+    pub session_id: Option<Uuid>,
+    pub created_by: String,
+    pub created_at: DateTime<Utc>,
+    pub expires_at: Option<DateTime<Utc>>,
+    pub status: String,
+    pub client_name: Option<String>,
+    pub client_machine: Option<String>,
+    pub connected_at: Option<DateTime<Utc>>,
+}
+
+/// Create a new support code
+pub async fn create_support_code(
+    pool: &PgPool,
+    code: &str,
+    created_by: &str,
+) -> Result<DbSupportCode, sqlx::Error> {
+    sqlx::query_as::<_, DbSupportCode>(
+        r#"
+        INSERT INTO connect_support_codes (code, created_by, status)
+        VALUES ($1, $2, 'pending')
+        RETURNING *
+        "#,
+    )
+    .bind(code)
+    .bind(created_by)
+    .fetch_one(pool)
+    .await
+}
+
+/// Get support code by code string
+pub async fn get_support_code(pool: &PgPool, code: &str) -> Result<Option<DbSupportCode>, sqlx::Error> {
+    sqlx::query_as::<_, DbSupportCode>(
+        "SELECT * FROM connect_support_codes WHERE code = $1"
+    )
+    .bind(code)
+    .fetch_optional(pool)
+    .await
+}
+
+/// Update support code when client connects
+pub async fn mark_code_connected(
+    pool: &PgPool,
+    code: &str,
+    session_id: Option<Uuid>,
+    client_name: Option<&str>,
+    client_machine: Option<&str>,
+) -> Result<(), sqlx::Error> {
+    sqlx::query(
+        r#"
+        UPDATE connect_support_codes SET
+            status = 'connected',
+            session_id = $1,
+            client_name = $2,
+            client_machine = $3,
+            connected_at = NOW()
+        WHERE code = $4
+        "#,
+    )
+    .bind(session_id)
+    .bind(client_name)
+    .bind(client_machine)
+    .bind(code)
+    .execute(pool)
+    .await?;
+    Ok(())
+}
+
+/// Mark support code as completed
+pub async fn mark_code_completed(pool: &PgPool, code: &str) -> Result<(), sqlx::Error> {
+    sqlx::query("UPDATE connect_support_codes SET status = 'completed' WHERE code = $1")
+        .bind(code)
+        .execute(pool)
+        .await?;
+    Ok(())
+}
+
+/// Mark support code as cancelled
+pub async fn mark_code_cancelled(pool: &PgPool, code: &str) -> Result<(), sqlx::Error> {
+    sqlx::query("UPDATE connect_support_codes SET status = 'cancelled' WHERE code = $1")
+        .bind(code)
+        .execute(pool)
+        .await?;
+    Ok(())
+}
+
+/// Get active support codes (pending or connected)
+pub async fn get_active_support_codes(pool: &PgPool) -> Result<Vec<DbSupportCode>, sqlx::Error> {
+    sqlx::query_as::<_, DbSupportCode>(
+        "SELECT * FROM connect_support_codes WHERE status IN ('pending', 'connected') ORDER BY created_at DESC"
+    )
+    .fetch_all(pool)
+    .await
+}
+
+/// Check if code exists and is valid for connection
+pub async fn is_code_valid(pool: &PgPool, code: &str) -> Result<bool, sqlx::Error> {
+    let result = sqlx::query_scalar::<_, bool>(
+        "SELECT EXISTS(SELECT 1 FROM connect_support_codes WHERE code = $1 AND status = 'pending')"
+    )
+    .bind(code)
+    .fetch_one(pool)
+    .await?;
+    Ok(result)
+}
+
+/// Check if code is cancelled
+pub async fn is_code_cancelled(pool: &PgPool, code: &str) -> Result<bool, sqlx::Error> {
+    let result = sqlx::query_scalar::<_, bool>(
+        "SELECT EXISTS(SELECT 1 FROM connect_support_codes WHERE code = $1 AND status = 'cancelled')"
+    )
+    .bind(code)
+    .fetch_one(pool)
+    .await?;
+    Ok(result)
+}
+
+/// Link session to support code
+pub async fn link_session_to_code(
+    pool: &PgPool,
+    code: &str,
+    session_id: Uuid,
+) -> Result<(), sqlx::Error> {
+    sqlx::query("UPDATE connect_support_codes SET session_id = $1 WHERE code = $2")
+        .bind(session_id)
+        .bind(code)
+        .execute(pool)
+        .await?;
+    Ok(())
+}