refactor(recipes): rename recipes, drop pi05_hirobot

- hirobot.yaml            -> subtasks_vqa.yaml
- hirobot_memory.yaml     -> subtask_mem_vqa_speech.yaml
- pi05_hirobot.yaml       -> deleted (stale: uses plan, top-camera names;
  superseded by the two recipes above)
- smolvla2_hirobot.yaml   -> deleted (was untracked stale junk)

Updated the smolvla2 / pi052 `recipe_path` config defaults, all
docstring / comment references, the annotation-pipeline + recipe docs,
and the three tests that loaded pi05_hirobot.yaml (repointed to the
renamed recipes; the low-level-branch and pipeline-render assertions
now accept a flow-only `low_level` stream as valid supervision, since
the new recipes' low_level_execution has no text-CE target).

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

docs/source/annotation_pipeline.mdx

@@ -72,7 +72,7 @@ The executor picks `LocalPipelineExecutor` for small datasets and
 ## Style-to-recipe consumer mapping
 
 The pipeline produces exactly the styles consumed by
-`src/lerobot/configs/recipes/pi05_hirobot.yaml`:
+`src/lerobot/configs/recipes/subtask_mem_vqa_speech.yaml`:
 
 - `low_level_execution`, `high_level_subtask`, `memory_update` consume
   `subtask`/`plan`/`memory` from `language_persistent`.

docs/source/language_and_recipes.mdx

@@ -101,7 +101,7 @@ The renderer does not apply a tokenizer chat template. Policy processors decide
 ## Blends
 
 Blend recipes select one weighted sub-recipe deterministically from the sample index.
-The canonical `recipes/pi05_hirobot.yaml` combines memory updates, interjection responses, high-level subtask prediction, low-level execution, and VQA.
+`recipes/subtasks_vqa.yaml` trains the core blend — high-level subtask prediction, low-level execution, and VQA. `recipes/subtask_mem_vqa_speech.yaml` is the fuller variant that also adds memory updates and spoken interjection responses.
 
 ## Graceful absence