chore: remove dead code, bump to 0.7.2

- Remove unused delete_master_key from crypto.rs
- Remove unused audit::log from audit.rs
- Simplify HistoryRow in rollback.rs (drop unused namespace/kind/name)
- Update AGENTS.md: audit::log → audit::log_tx

Made-with: Cursor

src/commands/rollback.rs

@@ -8,12 +8,6 @@ use crate::output::OutputMode;
 #[derive(FromRow)]
 struct HistoryRow {
     secret_id: Uuid,
-    #[allow(dead_code)]
-    namespace: String,
-    #[allow(dead_code)]
-    kind: String,
-    #[allow(dead_code)]
-    name: String,
     version: i64,
     action: String,
     tags: Vec<String>,
@@ -33,7 +27,7 @@ pub struct RollbackArgs<'a> {
 pub async fn run(pool: &PgPool, args: RollbackArgs<'_>, master_key: &[u8; 32]) -> Result<()> {
     let snap: Option<HistoryRow> = if let Some(ver) = args.to_version {
         sqlx::query_as(
-            "SELECT secret_id, namespace, kind, name, version, action, tags, metadata, encrypted \
+            "SELECT secret_id, version, action, tags, metadata, encrypted \
              FROM secrets_history \
              WHERE namespace = $1 AND kind = $2 AND name = $3 AND version = $4 \
              ORDER BY id DESC LIMIT 1",
@@ -46,7 +40,7 @@ pub async fn run(pool: &PgPool, args: RollbackArgs<'_>, master_key: &[u8; 32]) -
         .await?
     } else {
         sqlx::query_as(
-            "SELECT secret_id, namespace, kind, name, version, action, tags, metadata, encrypted \
+            "SELECT secret_id, version, action, tags, metadata, encrypted \
              FROM secrets_history \
              WHERE namespace = $1 AND kind = $2 AND name = $3 \
              ORDER BY id DESC LIMIT 1",