Add error handling for conda environment creation and spawn errors

Co-authored-by: eleanorjboyd <26030610+eleanorjboyd@users.noreply.github.com>

Author: Copilot

src/managers/conda/condaEnvManager.ts

@@ -191,6 +191,9 @@ export class CondaEnvManager implements EnvironmentManager, Disposable {
             return result;
         } catch (error) {
             this.log.error('Failed to create conda environment:', error);
+            showErrorMessage(
+                l10n.t('Failed to create conda environment: {0}', error instanceof Error ? error.message : String(error)),
+            );
             return undefined;
         }
     }

src/managers/conda/condaUtils.ts

@@ -212,6 +212,11 @@ async function _runConda(
         deferred.reject(new CancellationError());
     });
 
+    proc.on('error', (err) => {
+        log?.error(`Error spawning conda: ${err}`);
+        deferred.reject(new Error(`Error spawning conda: ${err.message}`));
+    });
+
     let stdout = '';
     let stderr = '';
     proc.stdout?.on('data', (data) => {