fix: add step.branch to documentation + test fixture

- DOCUMENTATION.md: added step.branch row to step types table
- plugin_test.go: added step.branch to expectedSteps list (50→51)

Fixes CI failure on v0.3.49 release.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: intel352

DOCUMENTATION.md

@@ -139,6 +139,7 @@ flowchart TD
 | `step.validate` | Validates pipeline data against required fields or JSON schema | pipelinesteps |
 | `step.transform` | Transforms data shape and field mapping | pipelinesteps |
 | `step.conditional` | Conditional branching based on field values | pipelinesteps |
+| `step.branch` | Switch/case routing with inline sub-pipeline execution | pipelinesteps |
 | `step.set` | Sets values in pipeline context with template support | pipelinesteps |
 | `step.log` | Logs pipeline data for debugging | pipelinesteps |
 | `step.publish` | Publishes events to EventBus | pipelinesteps |

plugins/pipelinesteps/plugin_test.go

@@ -81,6 +81,7 @@ func TestStepFactories(t *testing.T) {
 		"step.parallel",
 		"step.graphql",
 		"step.secret_fetch",
+		"step.branch",
 	}
 
 	for _, stepType := range expectedSteps {