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/lsp/mod.rs

@@ -70,7 +70,7 @@ impl LspManager {
         language_id: &str,
     ) -> anyhow::Result<()> {
         if self.servers.iter().any(|s| s.name == name) {
-            anyhow::bail!("LSP server '{}' is already connected", name);
+            anyhow::bail!("LSP server '{name}' is already connected");
         }
         let client = LspClient::spawn(command, args)?;
         self.servers.push(LspServer {
@@ -101,7 +101,7 @@ impl LspManager {
     pub fn disconnect(&mut self, name: &str) -> bool {
         if let Some(server) = self.servers.iter().find(|s| s.name == name) {
             if let Ok(mut client) = server.client.lock() {
-                let _ = client.shutdown();
+                client.shutdown();
             }
         }
         let len = self.servers.len();
@@ -134,7 +134,7 @@ impl LspManager {
     pub fn find_server_for_path(&self, path: &Path) -> Option<Arc<Mutex<LspClient>>> {
         path.extension()
             .and_then(|e| e.to_str())
-            .map(|s| format!(".{}", s))
+            .map(|s| format!(".{s}"))
             .and_then(|ext| self.find_server_for_extension(&ext))
     }
 
@@ -171,21 +171,15 @@ impl LspManager {
     /// Non-critical failures (file missing, server unreachable, send
     /// error) are logged with `tracing::warn!` rather than propagated,
     /// so a stale notification cannot abort the calling flow.
-    pub fn did_change_file(&mut self, path: &Path) -> anyhow::Result<()> {
-        let ext = match path.extension().and_then(|e| e.to_str()).map(|s| format!(".{}", s)) {
-            Some(ext) => ext,
-            None => {
-                tracing::warn!("did_change_file: path has no extension: {:?}", path);
-                return Ok(());
-            }
+    pub fn did_change_file(&mut self, path: &Path) {
+        let Some(ext) = path.extension().and_then(|e| e.to_str()).map(|s| format!(".{s}")) else {
+            tracing::warn!("did_change_file: path has no extension: {:?}", path);
+            return;
         };
 
-        let server_name = match self.extension_registry.get(&ext) {
-            Some(name) => name.clone(),
-            None => {
-                tracing::warn!("did_change_file: no LSP server registered for extension '{}'", ext);
-                return Ok(());
-            }
+        let server_name = if let Some(name) = self.extension_registry.get(&ext) { name.clone() } else {
+            tracing::warn!("did_change_file: no LSP server registered for extension '{}'", ext);
+            return;
         };
 
         let uri = path_to_lsp_uri(&path.to_string_lossy());
@@ -194,7 +188,7 @@ impl LspManager {
             Ok(t) => t,
             Err(e) => {
                 tracing::warn!("did_change_file: failed to read {:?}: {}", path, e);
-                return Ok(());
+                return;
             }
         };
 
@@ -202,12 +196,9 @@ impl LspManager {
             .get_language_id(&server_name)
             .unwrap_or_else(|| "plaintext".to_string());
 
-        let client = match self.get_client(&server_name) {
-            Some(c) => c,
-            None => {
-                tracing::warn!("did_change_file: server '{}' has no client", server_name);
-                return Ok(());
-            }
+        let Some(client) = self.get_client(&server_name) else {
+            tracing::warn!("did_change_file: server '{}' has no client", server_name);
+            return;
         };
 
         let next_version = match self.open_files.get(&uri) {
@@ -220,7 +211,7 @@ impl LspManager {
                 Ok(c) => c,
                 Err(e) => {
                     tracing::warn!("did_change_file: client mutex poisoned for '{}': {}", server_name, e);
-                    return Ok(());
+                    return;
                 }
             };
             if self.open_files.contains_key(&uri) {
@@ -237,7 +228,7 @@ impl LspManager {
                 uri,
                 e
             );
-            return Ok(());
+            return;
         }
 
         self.open_files.insert(
@@ -248,7 +239,6 @@ impl LspManager {
             },
         );
 
-        Ok(())
     }
 
     /// Record that `server_name` has an open document at `uri`.
@@ -274,9 +264,9 @@ impl LspManager {
     /// drop the vec. Failures from individual shutdowns are swallowed
     /// because the goal is best-effort termination during teardown.
     pub fn shutdown_all(&mut self) {
-        for server in self.servers.iter() {
+        for server in &self.servers {
             if let Ok(mut client) = server.client.lock() {
-                let _ = client.shutdown();
+                client.shutdown();
             }
         }
         self.servers.clear();