feat: user-scoped history/delete/rollback, dashboard & login UI, ignore *.pem

- Filter history/rollback/delete by user_id in secrets-core
- MCP tools/web pass user context; dashboard refresh; favicon static
- .gitignore *.pem; vscode tasks tweaks
- clippy: collapse else-if in rollback latest-history branch

Made-with: Cursor

crates/secrets-core/src/service/env_map.rs

@@ -107,11 +107,9 @@ fn env_prefix(entry: &Entry, prefix: &str) -> String {
     if prefix.is_empty() {
         name_part
     } else {
-        format!(
-            "{}_{}",
-            prefix.to_uppercase().replace(['-', '.', ' '], "_"),
-            name_part
-        )
+        let normalized = prefix.to_uppercase().replace(['-', '.', ' '], "_");
+        let normalized = normalized.trim_end_matches('_');
+        format!("{}_{}", normalized, name_part)
     }
 }