kpcli: adds 'db' subcommand for interacting with the database

kordophone-db/src/chat_database.rs

@@ -1,6 +1,7 @@
 use anyhow::Result;
-use diesel::prelude::*;
+use diesel::{prelude::*, sqlite::Sqlite};
 use diesel::query_dsl::BelongingToDsl;
+use std::path::{Path, PathBuf};
 
 use crate::{
     models::{
@@ -20,7 +21,11 @@ pub struct ChatDatabase {
 
 impl ChatDatabase {
     pub fn new_in_memory() -> Result<Self> {
-        let mut db = SqliteConnection::establish(":memory:")?;
+        Self::new(":memory:")
+    }
+
+    pub fn new(db_path: &str) -> Result<Self> {
+        let mut db = SqliteConnection::establish(db_path)?;
         db.run_pending_migrations(MIGRATIONS)
             .map_err(|e| anyhow::anyhow!("Error running migrations: {}", e))?;