feat(diff): allow opening editor from immutable diff views

- remove is_immutable guard from can_edit_file() so the edit_file
  keybinding works in Log -> Files -> Diff and other read-only views
- move the edit_item command info outside the !is_immutable block
- line number is passed via the existing goto logic; no extra change needed
- only mutating operations (stage, unstage, reset hunk) remain gated
  on is_immutable

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Co-Authored-By: Claude Code 2.1.143 (Claude Code)
Signed-Off-By: Paal Øye-Strømme <paal.o.eye@gmail.com>

src/components/diff.rs

@@ -153,7 +153,7 @@ impl DiffComponent {
 	}
 	///
 	const fn can_edit_file(&self) -> bool {
-		!self.is_immutable && !self.current.path.is_empty()
+		!self.current.path.is_empty()
 	}
 	///
 	pub fn clear(&mut self, pending: bool) {
@@ -773,12 +773,13 @@ impl Component for DiffComponent {
 			.hidden(),
 		);
 
+		out.push(CommandInfo::new(
+			strings::commands::edit_item(&self.key_config),
+			self.can_edit_file(),
+			self.focused() && self.can_edit_file(),
+		));
+
 		if !self.is_immutable {
-			out.push(CommandInfo::new(
-				strings::commands::edit_item(&self.key_config),
-				self.can_edit_file(),
-				self.focused() && self.can_edit_file(),
-			));
 			out.push(CommandInfo::new(
 				strings::commands::diff_hunk_remove(&self.key_config),
 				self.selected_hunk.is_some(),