chore: auto-commit (286 archivos)

- .claude/agents/fn-orquestador/SKILL.md
- .claude/commands/fn_claude.md
- .claude/rules/INDEX.md
- .claude/rules/cpp_apps.md
- .claude/rules/ids_naming.md
- CHANGELOG.md
- apps/dag_engine/README.md
- apps/dag_engine/api.go
- apps/dag_engine/dags_migrated/example.yaml
- apps/dag_engine/dags_migrated/example_lineage_tracking.yaml
- ...

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

functions/core/dag_validate.go

@@ -1,6 +1,13 @@
 package core
 
-import "fmt"
+import (
+	"fmt"
+	"regexp"
+)
+
+// functionIDPattern matches registry IDs in `<name>_<lang>_<domain>` form.
+// Compiled once and reused across validations.
+var functionIDPattern = regexp.MustCompile(`^[a-z0-9_]+_[a-z]+_[a-z]+$`)
 
 // DagValidate validates a DagDefinition for structural correctness.
 // Checks: steps have name/ID, no duplicate names/IDs, all depends reference
@@ -31,6 +38,19 @@ func DagValidate(dag DagDefinition) DagValidationResult {
 			result.Warnings = append(result.Warnings,
 				fmt.Sprintf("step %q: has both command and script", ref))
 		}
+
+		// Function-step validation.
+		if step.Function != "" {
+			if !functionIDPattern.MatchString(step.Function) {
+				result.Errors = append(result.Errors,
+					fmt.Sprintf("step %s: invalid function id format: %s", ref, step.Function))
+				result.Valid = false
+			}
+			if step.Command != "" || step.Script != "" {
+				result.Warnings = append(result.Warnings,
+					fmt.Sprintf("step %s: function takes precedence; command/script ignored", ref))
+			}
+		}
 	}
 
 	if !result.Valid {