ci: add GitHub Actions workflows with semantic-release auto-versioning

chore: fix all 702 clippy warnings across codebase
- auto-fix 475 via cargo clippy --fix
- fix remaining 227 manually: uninlined_format_args, redundant_closure, match_same_arms,
  underscore_binding, format_push_string, items_after_statements, needless_pass_by_value,
  clone_on_copy, case_sensitive_extension, single_match/let-else, write_with_newline,
  and other clippy lints

src/app/runtime/commands.rs

@@ -75,7 +75,7 @@ pub fn apply_command(command: Command) -> Vec<Action> {
         Command::Unknown(cmd) => {
             vec![Action::SystemNote {
                 kind: "error".to_string(),
-                message: format!("unknown command: {}", cmd),
+                message: format!("unknown command: {cmd}"),
             }]
         }
     }