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/cron_explain.md

@@ -0,0 +1,61 @@
+---
+name: cron_explain
+kind: function
+lang: go
+domain: core
+version: "1.0.0"
+purity: pure
+signature: "func CronExplain(expr string) string"
+description: "Convierte una expresion cron (5 campos o shortcut @daily/@hourly/etc.) en una frase humana corta. Reconoce patrones comunes: every N minutes/hours, daily/weekdays at HH:MM, y shortcuts. Devuelve el expr crudo si no encaja en ningun patron. Sin dependencias externas, solo stdlib."
+tags: ["cron", "scheduler", "humanize"]
+uses_functions: []
+uses_types: []
+returns: []
+returns_optional: false
+error_type: ""
+imports: ["fmt", "strconv", "strings"]
+tested: true
+tests:
+  - "every 15 minutes"
+  - "daily at 00:00"
+  - "weekdays at 09:00"
+  - "every 30 minutes"
+  - "every 2 hours"
+  - "shortcut @hourly"
+  - "shortcut @daily"
+  - "shortcut @weekly"
+  - "shortcut @monthly"
+  - "unknown returns raw"
+  - "invalid too few fields"
+  - "every minute"
+  - "daily at 14:30"
+  - "every hour zero min"
+  - "shortcut @midnight"
+  - "weekdays at 08:00"
+test_file_path: "functions/core/cron_explain_test.go"
+file_path: "functions/core/cron_explain.go"
+params:
+  - name: expr
+    desc: "Expresion cron de 5 campos (min hora dom mes dow) o shortcut (@hourly, @daily, @weekly, @monthly, @yearly). Se ignoran campos extra (6to campo segundos/year)."
+output: "Frase legible en ingles: 'every N minutes', 'daily at HH:MM', 'weekdays at HH:MM', 'hourly', 'daily', 'weekly', 'monthly'. Devuelve expr sin modificar si el patron no es reconocido."
+---
+
+## Ejemplo
+
+```go
+fmt.Println(CronExplain("*/15 * * * *"))  // every 15 minutes
+fmt.Println(CronExplain("0 0 * * *"))     // daily at 00:00
+fmt.Println(CronExplain("0 9 * * 1-5"))   // weekdays at 09:00
+fmt.Println(CronExplain("*/30 * * * *"))  // every 30 minutes
+fmt.Println(CronExplain("0 */2 * * *"))   // every 2 hours
+fmt.Println(CronExplain("@hourly"))        // hourly
+fmt.Println(CronExplain("5 4 * * 0"))     // 5 4 * * 0  (not recognized, returned raw)
+```
+
+## Cuando usarla
+
+Cuando necesites mostrar al usuario una descripcion legible de un schedule cron en una UI, log o CLI. Antes de renderizar un campo `cron_expr` en un dashboard o TUI.
+
+## Gotchas
+
+Funcion pura — nunca falla ni entra en panico. Patrones reconocidos son los comunes; expresiones con listas (`1,3,5`), rangos en horas, o combinaciones complejas devuelven el expr crudo sin error.