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/tool/bash_tools.rs

@@ -43,7 +43,7 @@ impl Tool for BashOutput {
         }
         match crate::app::bgbash::control::bash_output(&job_id) {
             Some(lines) => Ok(lines.join("\n")),
-            None => Ok(format!("No new output from job '{}'", job_id)),
+            None => Ok(format!("No new output from job '{job_id}'")),
         }
     }
 }
@@ -82,11 +82,11 @@ impl Tool for BashKill {
             anyhow::bail!("invalid job_id format: expected UUID");
         }
         crate::app::bgbash::control::bash_kill(&job_id)?;
-        Ok(format!("Killed background job '{}'", job_id))
+        Ok(format!("Killed background job '{job_id}'"))
     }
 }
 
-/// Validate that a job_id matches UUID v4 format (hex with dashes).
+/// Validate that a `job_id` matches UUID v4 format (hex with dashes).
 fn is_valid_job_id(id: &str) -> bool {
     // UUID v4 format: 8-4-4-4-12 hex digits
     let parts: Vec<&str> = id.split('-').collect();