fix(test): align --no-input write assertion to new error message

Commit be8188b ("fix: harden TTY and output-discipline across CLI
surface") rewrote the --interactive-in-non-TTY error message from
"not supported in non-interactive mode" to the more actionable
"--interactive requires an interactive terminal. Run without
--interactive in CI or non-TTY environments, or pipe input via
stdin."

The unit test in tests/unit/register-write.test.ts was updated in
that commit, but the e2e and integration tests were missed. Both
assert on the write --interactive --no-input failure path.

Match on the stable fragment "requires an interactive terminal"
rather than the full sentence, for drift resilience against future
wording tweaks. The adjacent init assertions keep their "not
supported in non-interactive mode" phrasing — that message still
applies to register-init.ts:25 and is unchanged.

Author: sjsyrek

tests/e2e/cli-no-input.e2e.test.ts

@@ -44,7 +44,7 @@ describe('--no-input E2E', () => {
         execSync('deepl --no-input write "test" --interactive', { encoding: 'utf-8', stdio: 'pipe' });
       } catch (error: any) {
         expect(error.status).toBe(6);
-        expect(error.stderr.toString()).toContain('not supported in non-interactive mode');
+        expect(error.stderr.toString()).toContain('requires an interactive terminal');
       }
     });
   });

tests/integration/cli-no-input.integration.test.ts

@@ -32,7 +32,7 @@ describe('--no-input flag', () => {
       const result = runCLIExpectError('deepl --no-input write "test text" --interactive');
 
       expect(result.status).toBe(6);
-      expect(result.output).toContain('not supported in non-interactive mode');
+      expect(result.output).toContain('requires an interactive terminal');
     });
   });