feat(core): entry 历史附带关联 secret 密文快照，rollback 可恢复 N:N 与密文

- db: metadata_with_secret_snapshot / strip / parse 辅助
- add/update/delete/rollback 在写 entries_history 前合并快照
- rollback: 按历史快照同步 entry_secrets、更新或插入 secrets
- 满足 clippy collapsible_if

crates/secrets-core/src/db.rs

@@ -1,7 +1,7 @@
 use std::str::FromStr;
 
 use anyhow::{Context, Result};
-use serde_json::Value;
+use serde_json::{Map, Value};
 use sqlx::PgPool;
 use sqlx::postgres::{PgConnectOptions, PgPoolOptions, PgSslMode};
 
@@ -562,4 +562,75 @@ pub async fn snapshot_secret_history(
     Ok(())
 }
 
+pub const ENTRY_HISTORY_SECRETS_KEY: &str = "__secrets_snapshot_v1";
+
+#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
+pub struct EntrySecretSnapshot {
+    pub name: String,
+    #[serde(rename = "type")]
+    pub secret_type: String,
+    pub encrypted_hex: String,
+}
+
+pub async fn metadata_with_secret_snapshot(
+    tx: &mut sqlx::Transaction<'_, sqlx::Postgres>,
+    entry_id: uuid::Uuid,
+    metadata: &Value,
+) -> Result<Value> {
+    #[derive(sqlx::FromRow)]
+    struct Row {
+        name: String,
+        #[sqlx(rename = "type")]
+        secret_type: String,
+        encrypted: Vec<u8>,
+    }
+
+    let rows: Vec<Row> = sqlx::query_as(
+        "SELECT s.name, s.type, s.encrypted \
+         FROM entry_secrets es \
+         JOIN secrets s ON s.id = es.secret_id \
+         WHERE es.entry_id = $1 \
+         ORDER BY s.name ASC",
+    )
+    .bind(entry_id)
+    .fetch_all(&mut **tx)
+    .await?;
+
+    let snapshots: Vec<EntrySecretSnapshot> = rows
+        .into_iter()
+        .map(|r| EntrySecretSnapshot {
+            name: r.name,
+            secret_type: r.secret_type,
+            encrypted_hex: ::hex::encode(r.encrypted),
+        })
+        .collect();
+
+    let mut merged = match metadata.clone() {
+        Value::Object(obj) => obj,
+        _ => Map::new(),
+    };
+    merged.insert(
+        ENTRY_HISTORY_SECRETS_KEY.to_string(),
+        serde_json::to_value(snapshots)?,
+    );
+    Ok(Value::Object(merged))
+}
+
+pub fn strip_secret_snapshot_from_metadata(metadata: &Value) -> Value {
+    let mut m = match metadata.clone() {
+        Value::Object(obj) => obj,
+        _ => return metadata.clone(),
+    };
+    m.remove(ENTRY_HISTORY_SECRETS_KEY);
+    Value::Object(m)
+}
+
+pub fn entry_secret_snapshot_from_metadata(metadata: &Value) -> Option<Vec<EntrySecretSnapshot>> {
+    let Value::Object(map) = metadata else {
+        return None;
+    };
+    let raw = map.get(ENTRY_HISTORY_SECRETS_KEY)?;
+    serde_json::from_value(raw.clone()).ok()
+}
+
 // ── DB helpers ────────────────────────────────────────────────────────────────