refactor: restructure to clean architecture

fix: restore ScoringConfig improvements lost in refactor commit

docs: rewrite README and CLAUDE.md to reflect current architecture

code-format

code fixes

bin/import-portfolio.js

@@ -0,0 +1,36 @@
+/**
+ * bin/import-portfolio.js — Portfolio CSV Importer
+ *
+ * Reads a holdings export from Robinhood, Vanguard, or Fidelity
+ * and merges the positions into portfolio.json.
+ *
+ * Broker is auto-detected from CSV headers.
+ * Existing entries are updated in-place; new tickers are added.
+ *
+ * How to export:
+ *   Robinhood  → Account → Statements & History → Export → Holdings
+ *   Vanguard   → My Accounts → Holdings → Download (top-right icon)
+ *   Fidelity   → Accounts & Trade → Portfolio → Positions → Download CSV
+ *
+ * Usage:
+ *   npm run import-portfolio -- <file.csv>
+ */
+
+import { PortfolioImporter } from '../src/finance/PortfolioImporter.js';
+
+const csvPath = process.argv[2];
+
+if (!csvPath) {
+  console.error('Usage: npm run import-portfolio -- <path-to-csv>\n');
+  console.error('Examples:');
+  console.error('  npm run import-portfolio -- ~/Downloads/robinhood_holdings.csv');
+  console.error('  npm run import-portfolio -- ~/Downloads/vanguard_holdings.csv');
+  process.exit(1);
+}
+
+try {
+  new PortfolioImporter().import(csvPath);
+} catch (err) {
+  console.error(`\nImport failed: ${err.message}`);
+  process.exit(1);
+}