Function initializeAnalysisDirectory

initializeAnalysisDirectory(baseDir: string, date: string): string
Initialize the analysis-output/{date}/ directory structure.

Creates the following sub-directories if they do not already exist:
- classification/ — Political classification results
- data/ — Raw downloaded data cache
- threat-assessment/ — Political threat analysis (Issue 2)
- risk-scoring/ — Quantitative risk assessment (Issue 3)
Parameters
- baseDir: string
  Base directory for analysis output (typically analysis-output/)
- date: string
  ISO date string used as the run folder name (YYYY-MM-DD). Must match ^\d{4}-\d{2}-\d{2}$; rejects path-separator or traversal values.
Returns string
Path to the date-stamped run directory (relative or absolute depending on baseDir)
Throws
If date does not match YYYY-MM-DD format
Example
```
const runDir = initializeAnalysisDirectory('./analysis-output', '2026-03-26');
// Creates: ./analysis-output/2026-03-26/classification/
//          ./analysis-output/2026-03-26/data/
//          ./analysis-output/2026-03-26/threat-assessment/
//          ./analysis-output/2026-03-26/risk-scoring/
```
- Defined in utils/political-classification.ts:901