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-mcp/src/tools.rs

@@ -555,9 +555,9 @@ impl SecretsService {
     }
 
     #[tool(
-        description = "Preview the environment variable mapping that would be injected when \
-        running a command. Requires X-Encryption-Key header. \
-        Shows variable names and sources, useful for debugging."
+        description = "Build the environment variable map from entry secrets with decrypted \
+        plaintext values. Requires X-Encryption-Key header. \
+        Returns a JSON object of VAR_NAME -> plaintext_value ready for injection."
     )]
     async fn secrets_env_map(
         &self,