fix(docs/pt-BR): replace untranslated code block placeholders (#5781)

* fix(docs/pt-BR): replace untranslated code block placeholders

Replace all `# (O código não é traduzido)` and `# código não traduzido`
placeholder comments in the PT-BR docs with the actual code from the
English source files.

Files fixed:
- docs/pt-BR/concepts/flows.mdx (~15 placeholders → real code)
- docs/pt-BR/guides/flows/mastering-flow-state.mdx (~17 placeholders → real code)

Code itself is kept in English per i18n conventions. Inline # comments
within code blocks have been translated to Portuguese.

* fix(docs/pt-BR): address CodeRabbit review comments

- flows.mdx: add missing load_dotenv() call after imports
- mastering-flow-state.mdx: fix PersistentCounterFlow second-run example
  to pass inputs={"id": flow1.state.id} to kickoff(), matching the
  documented resume pattern; update comment accordingly