fix(tui): bounds-check scope picker selected index

Replace direct indexing (self.projects[self.selected_index - 1]) with
.get() to prevent panic if selected_index is somehow out of bounds.
Falls back to "All Projects" scope when the index is invalid instead
of panicking.

crates/lore-tui/src/state/scope_picker.rs

@@ -76,12 +76,17 @@ impl ScopePickerState {
                 project_id: None,
                 project_name: None,
             }
-        } else {
+        } else if let Some(project) = self.projects.get(self.selected_index - 1) {
-            let project = &self.projects[self.selected_index - 1];
             ScopeContext {
                 project_id: Some(project.id),
                 project_name: Some(project.path.clone()),
             }
+        } else {
+            // Out-of-bounds — fall back to "All Projects".
+            ScopeContext {
+                project_id: None,
+                project_name: None,
+            }
         }
     }