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/controller/command.rs

@@ -87,7 +87,7 @@ pub fn parse_command(text: &str) -> Command {
                 mode: arg1.to_string(),
             }
         }
-        "/pipeline" => Command::Unknown(format!("/pipeline {} (use: full|quick|skip)", arg1)),
+        "/pipeline" => Command::Unknown(format!("/pipeline {arg1} (use: full|quick|skip)")),
         _ => Command::Unknown(cmd.to_string()),
     }
 }

src/controller/input.rs

@@ -21,6 +21,7 @@ use crate::controller::command::parse_command;
 /// Why: when Editor overlay is active, all key events are consumed by the
 /// editor handler and never reach the main action dispatch. Return `Vec`
 /// so that a single key press can trigger multiple actions.
+#[allow(clippy::too_many_lines)]
 pub fn handle_key(key: KeyEvent, state: &mut AppStateRest) -> Vec<Action> {
     // While Editor overlay is active, route input directly to the editor handler
     if state.misc.overlay == Overlay::Editor {
@@ -34,7 +35,7 @@ pub fn handle_key(key: KeyEvent, state: &mut AppStateRest) -> Vec<Action> {
                     if let Err(e) = std::fs::write(&ed.path, &content) {
                         state.push_toast(crate::app::state::types::Toast::new(
                             crate::app::state::types::ToastKind::Error,
-                            format!("Save failed: {}", e),
+                            format!("Save failed: {e}"),
                         ));
                     } else {
                         state.push_toast(crate::app::state::types::Toast::new(
@@ -58,11 +59,11 @@ pub fn handle_key(key: KeyEvent, state: &mut AppStateRest) -> Vec<Action> {
                 return vec![];
             }
             KeyCode::Enter => {
-                crate::app::mode::editor::handle_editor_input(state, "\n".to_string());
+                crate::app::mode::editor::handle_editor_input(state, "\n");
                 return vec![];
             }
             KeyCode::Char(c) => {
-                crate::app::mode::editor::handle_editor_input(state, c.to_string());
+                crate::app::mode::editor::handle_editor_input(state, &c.to_string());
                 return vec![];
             }
             _ => return vec![],
@@ -93,25 +94,15 @@ pub fn handle_key(key: KeyEvent, state: &mut AppStateRest) -> Vec<Action> {
             }
             KeyCode::Enter | KeyCode::Char('a') => {
                 let items = crate::app::mode::learning::get_learning_items(state);
-                if let Some(item) = items.get(state.misc.selected_index) {
-                    match item {
-                        crate::app::mode::learning::LearningItem::Pending { name, .. } => {
-                            return vec![Action::LessonAccept { name: name.clone() }];
-                        }
-                        _ => {}
-                    }
+                if let Some(crate::app::mode::learning::LearningItem::Pending { name, .. }) = items.get(state.misc.selected_index) {
+                    return vec![Action::LessonAccept { name: name.clone() }];
                 }
                 return vec![];
             }
             KeyCode::Char('r') => {
                 let items = crate::app::mode::learning::get_learning_items(state);
-                if let Some(item) = items.get(state.misc.selected_index) {
-                    match item {
-                        crate::app::mode::learning::LearningItem::Pending { name, .. } => {
-                            return vec![Action::LessonReject { name: name.clone() }];
-                        }
-                        _ => {}
-                    }
+                if let Some(crate::app::mode::learning::LearningItem::Pending { name, .. }) = items.get(state.misc.selected_index) {
+                    return vec![Action::LessonReject { name: name.clone() }];
                 }
                 return vec![];
             }
@@ -341,8 +332,8 @@ fn handle_overlay_enter(state: &mut AppStateRest) -> Vec<Action> {
                         tracing::warn!("[input] provider '{}' has no default_model, using 'claude-opus-4-8'", provider);
                         "claude-opus-4-8".to_string()
                     });
-                    state.settings.provider = provider.clone();
-                    state.settings.model = model.clone();
+                    state.settings.provider.clone_from(provider);
+                    state.settings.model.clone_from(&model);
                     if let Some(ref key) = cfg.default_api_key {
                         state.settings.api_keys.insert(provider.clone(), key.clone());
                     } else if let Some(env_key) = cfg.api_key_env.as_ref().and_then(|env| std::env::var(env).ok()) {
@@ -351,7 +342,7 @@ fn handle_overlay_enter(state: &mut AppStateRest) -> Vec<Action> {
                     let _ = state.settings.save();
                     state.push_toast(crate::app::state::types::Toast::new(
                         crate::app::state::types::ToastKind::Success,
-                        format!("Switched to {} / {}", provider, model),
+                        format!("Switched to {provider} / {model}"),
                     ));
                 }
             }