refactor: 消除冗余、统一设计，bump 0.9.1

- 提取 EntryRow/SecretFieldRow 到 models.rs
- 提取 current_actor()、print_json() 公共函数
- ExportFormat::from_extension 复用 from_str
- fetch_entries 默认 limit 100k（export/inject/run 不再截断）
- history 独立为 history.rs 模块
- delete 改用 DeleteArgs 结构体
- config_dir 改为 Result，Argon2id 参数提取常量
- Cargo 依赖 ^ 前缀、tokio 精简 features
- 更新 AGENTS.md 项目结构

Made-with: Cursor

src/models.rs

@@ -38,6 +38,27 @@ pub struct SecretField {
     pub updated_at: DateTime<Utc>,
 }
 
+// ── Internal query row types (shared across commands) ─────────────────────────
+
+/// Minimal entry row fetched for write operations (add / update / delete / rollback).
+#[derive(Debug, sqlx::FromRow)]
+pub struct EntryRow {
+    pub id: Uuid,
+    pub version: i64,
+    pub tags: Vec<String>,
+    pub metadata: Value,
+}
+
+/// Minimal secret field row fetched before snapshots or cascade deletes.
+#[derive(Debug, sqlx::FromRow)]
+pub struct SecretFieldRow {
+    pub id: Uuid,
+    pub field_name: String,
+    pub field_type: String,
+    pub value_len: i32,
+    pub encrypted: Vec<u8>,
+}
+
 // ── Export / Import types ──────────────────────────────────────────────────────
 
 /// Supported file formats for export/import.
@@ -52,15 +73,12 @@ impl ExportFormat {
     /// Infer format from file extension (.json / .toml / .yaml / .yml).
     pub fn from_extension(path: &str) -> anyhow::Result<Self> {
         let ext = path.rsplit('.').next().unwrap_or("").to_lowercase();
-        match ext.as_str() {
-            "json" => Ok(Self::Json),
-            "toml" => Ok(Self::Toml),
-            "yaml" | "yml" => Ok(Self::Yaml),
-            other => anyhow::bail!(
+        Self::from_str(&ext).map_err(|_| {
+            anyhow::anyhow!(
                 "Cannot infer format from extension '.{}'. Use --format json|toml|yaml",
-                other
-            ),
-        }
+                ext
+            )
+        })
     }
 
     /// Parse from --format CLI value.
@@ -146,16 +164,12 @@ pub fn json_to_toml_value(v: &Value) -> anyhow::Result<toml::Value> {
         }
         Value::String(s) => Ok(toml::Value::String(s.clone())),
         Value::Array(arr) => {
-            // Check for uniform scalar type (TOML requires homogeneous arrays at the value level,
-            // though arrays of tables are handled separately via TOML's [[table]] syntax).
-            // For simplicity we convert each element; if types are mixed, toml crate will
-            // handle it gracefully or we fall back to a JSON string.
             let items: anyhow::Result<Vec<toml::Value>> =
                 arr.iter().map(json_to_toml_value).collect();
             match items {
                 Ok(vals) => Ok(toml::Value::Array(vals)),
-                Err(_) => {
-                    // Fallback: serialise as JSON string
+                Err(e) => {
+                    tracing::debug!(error = %e, "mixed-type array; falling back to JSON string");
                     Ok(toml::Value::String(serde_json::to_string(v)?))
                 }
             }
@@ -171,8 +185,8 @@ pub fn json_to_toml_value(v: &Value) -> anyhow::Result<toml::Value> {
                     Ok(tv) => {
                         toml_map.insert(k.clone(), tv);
                     }
-                    Err(_) => {
-                        // Fallback: serialise as JSON string
+                    Err(e) => {
+                        tracing::debug!(key = %k, error = %e, "field not representable in TOML; falling back to JSON string");
                         toml_map
                             .insert(k.clone(), toml::Value::String(serde_json::to_string(val)?));
                     }