chore: auto-commit (57 archivos)

- frontend/functions/core/format_datetime_short.md
- frontend/functions/core/format_datetime_short.test.ts
- frontend/functions/core/format_datetime_short.ts
- frontend/functions/core/format_duration.md
- frontend/functions/core/format_duration.test.ts
- frontend/functions/core/format_duration.ts
- frontend/functions/core/month_grid.md
- frontend/functions/core/month_grid.test.ts
- frontend/functions/core/month_grid.ts
- frontend/functions/core/string_hash_palette.md
- ...

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

functions/infra/http_session_cookie_set.md

@@ -0,0 +1,48 @@
+---
+name: http_session_cookie_set
+kind: function
+lang: go
+domain: infra
+version: "1.0.0"
+purity: impure
+signature: "func SessionCookieSet(w http.ResponseWriter, name, token string, expiresAt int64)"
+description: "Escribe una cookie de sesion HttpOnly en la respuesta HTTP. Path='/', SameSite=Lax, Expires=time.Unix(expiresAt,0). No retorna error porque http.SetCookie no falla en runtime."
+tags: [http, session, cookie, auth, response]
+uses_functions: []
+uses_types: []
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: ["net/http", "time"]
+params:
+  - name: w
+    desc: "ResponseWriter donde se escribe el header Set-Cookie"
+  - name: name
+    desc: "nombre de la cookie (p.ej. 'kanban_session')"
+  - name: token
+    desc: "valor del token de sesion"
+  - name: expiresAt
+    desc: "timestamp Unix (segundos) de expiracion de la cookie"
+output: "escribe el header Set-Cookie en w; sin valor de retorno"
+tested: true
+tests:
+  - "cookie set con nombre y token correctos"
+  - "header Set-Cookie contiene HttpOnly y SameSite=Lax"
+test_file_path: "functions/infra/http_session_cookie_set_test.go"
+file_path: "functions/infra/http_session_cookie_set.go"
+---
+
+## Ejemplo
+
+```go
+sess, err := infra.SessionCreate(db, userID, 7*24*time.Hour, nil)
+if err != nil {
+    http.Error(w, "internal error", 500)
+    return
+}
+infra.SessionCookieSet(w, "my_session", sess.Token, sess.ExpiresAt)
+```
+
+## Notas
+
+Extraido de apps/kanban/backend/auth.go. La funcion no retorna error porque `http.SetCookie` escribe directamente en los headers del ResponseWriter y nunca falla. El campo `error_type` se omite porque la firma no tiene retorno de error — hay precedente en el registry (componentes C++ y otros helpers HTTP impuros sin error_type).