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_clear.md

@@ -0,0 +1,49 @@
+---
+name: http_session_cookie_clear
+kind: function
+lang: go
+domain: infra
+version: "1.0.0"
+purity: impure
+signature: "func SessionCookieClear(w http.ResponseWriter, name string)"
+description: "Invalida la cookie de sesion en el browser fijando MaxAge=-1. Path='/', HttpOnly=true, SameSite=Lax. No retorna error porque http.SetCookie no falla en runtime."
+tags: [http, session, cookie, auth, logout, response]
+uses_functions: []
+uses_types: []
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: ["net/http"]
+params:
+  - name: w
+    desc: "ResponseWriter donde se escribe el header Set-Cookie"
+  - name: name
+    desc: "nombre de la cookie a invalidar (debe coincidir con el nombre usado al crearla)"
+output: "escribe el header Set-Cookie con MaxAge=-1 en w; sin valor de retorno"
+tested: true
+tests:
+  - "cookie clear setea MaxAge negativo"
+  - "cookie clear valor es vacio"
+  - "header Set-Cookie contiene HttpOnly y SameSite=Lax"
+test_file_path: "functions/infra/http_session_cookie_clear_test.go"
+file_path: "functions/infra/http_session_cookie_clear.go"
+---
+
+## Ejemplo
+
+```go
+func handleLogout(db *DB) http.HandlerFunc {
+    return func(w http.ResponseWriter, r *http.Request) {
+        token := infra.SessionTokenExtract(r, "my_session")
+        if token != "" {
+            _ = infra.SessionDelete(db.conn, token)
+        }
+        infra.SessionCookieClear(w, "my_session")
+        w.WriteHeader(http.StatusNoContent)
+    }
+}
+```
+
+## Notas
+
+Extraido de apps/kanban/backend/auth.go. MaxAge=-1 hace que el browser elimine la cookie inmediatamente independientemente de la fecha Expires original. La funcion no retorna error porque `http.SetCookie` escribe directamente en los headers y nunca falla. Complemento de `http_session_cookie_set_go_infra`.