+ secret & metadata migration

.gitignore

@@ -9,3 +9,4 @@ target/
 go_client/openapi.json
 crates/storage-sled/sled_db
 test.db
+src/storage/database.db

migrations/20240501152243_KvSecret.sql

@@ -0,0 +1,28 @@
+-- Add migration script here
+
+CREATE TABLE metadata (
+    secret_path TEXT PRIMARY KEY NOT NULL,
+
+    cas_required INTEGER NOT NULL, -- no bool datatype in sqlite
+    created_time TIMESTAMP NOT NULL,
+    delete_version_after TEXT, -- Maybe NOT NULL
+    max_versions INTEGER NOT NULL,
+    -- current_version INTEGER NOT NULL,
+    -- oldest_version INTEGER NOT NULL,
+    updated_time TIMESTAMP NOT NULL,
+    custom_data TEXT
+);
+
+CREATE TABLE secret_versions (
+    secret_data TEXT NOT NULL,
+    
+    created_time TIMESTAMP NOT NULL,
+    deletion_time TIMESTAMP,
+
+    version_number INTEGER NOT NULL DEFAULT 0,
+    secret_path TEXT NOT NULL,
+    PRIMARY KEY (secret_path, version_number),
+    FOREIGN KEY (secret_path) REFERENCES metadata(secret_path)
+);
+
+CREATE INDEX idx_secret_versions_secret_path ON secret_versions (secret_path);

src/engines/kv/structs.rs

@@ -1,6 +1,6 @@
 use chrono::{DateTime, Utc};
 use serde::{Deserialize, Serialize};
-use std::{collections::HashMap, hash::Hash, vec};
+use std::{collections::HashMap, vec};
 
 #[derive(Serialize, Deserialize, Debug)]
 pub struct KvSecret {