Task: pick which Analyses to run to answer the analyst's question.

Given the question, the list of warehouse tables, the metric catalog, and the catalog of available Analyses (each with a name, description, and args schema), choose the smallest set of Analyses whose combined output will produce a defensible answer.

Output: a JSON object with exactly this shape, in one fenced ```json block:
{
  "rationale": "<one sentence on why this plan>",
  "steps": [
    {"analysis": "<analysis_name>", "args": { ... }, "why": "<one sentence>"}
  ]
}

Rules:
- Only use analyses that appear in the catalog. If none fits the question well, pick `direct_answer`.
- The `args` keys must match the analysis's args_schema; additional keys are ignored, missing optional ones are fine.
- Most questions are single-step. Only chain analyses when the second genuinely needs the first's output.
- Comparing two periods is ONE `compare_periods` step, not two `direct_answer` steps.