chore: remove field_type and value_len from secrets schema

- Drop field_type, value_len from secrets and secrets_history tables
- Remove infer_field_type, compute_value_len from add.rs
- Simplify search output to field names only
- Update AGENTS.md, README.md documentation

Bump version to 0.9.4

Made-with: Cursor

src/commands/search.rs

@@ -250,8 +250,8 @@ async fn fetch_entries_paged(pool: &PgPool, a: PagedFetchArgs<'_>) -> Result<Vec
 
 // ── Secret schema fetching (no master key) ───────────────────────────────────
 
-/// Fetch secret field schemas (field_name, field_type, value_len) for a set of entry ids.
-/// Returns a map from entry_id to list of SecretField (encrypted field not used here).
+/// Fetch secret field names for a set of entry ids.
+/// Returns a map from entry_id to list of SecretField.
 async fn fetch_secret_schemas(
     pool: &PgPool,
     entry_ids: &[uuid::Uuid],
@@ -423,8 +423,6 @@ fn to_json(entry: &Entry, summary: bool, schema: Option<&[SecretField]>) -> Valu
                 .map(|f| {
                     json!({
                         "field_name": f.field_name,
-                        "field_type": f.field_type,
-                        "value_len": f.value_len,
                     })
                 })
                 .collect();
@@ -474,10 +472,7 @@ fn print_text(entry: &Entry, summary: bool, schema: Option<&[SecretField]>) -> R
         }
         match schema {
             Some(fields) if !fields.is_empty() => {
-                let schema_str: Vec<String> = fields
-                    .iter()
-                    .map(|f| format!("{}: {}({})", f.field_name, f.field_type, f.value_len))
-                    .collect();
+                let schema_str: Vec<String> = fields.iter().map(|f| f.field_name.clone()).collect();
                 println!("  secrets:  {}", schema_str.join(", "));
                 println!("            (use `secrets inject` or `secrets run` to get values)");
             }
@@ -556,8 +551,6 @@ mod tests {
             id: Uuid::nil(),
             entry_id: Uuid::nil(),
             field_name: "token".to_string(),
-            field_type: "string".to_string(),
-            value_len: 6,
             encrypted: enc,
             version: 1,
             created_at: Utc::now(),
@@ -597,8 +590,6 @@ mod tests {
         let secrets = v.get("secrets").unwrap().as_array().unwrap();
         assert_eq!(secrets.len(), 1);
         assert_eq!(secrets[0]["field_name"], "token");
-        assert_eq!(secrets[0]["field_type"], "string");
-        assert_eq!(secrets[0]["value_len"], 6);
     }
 
     #[test]