Feat: Wire frontend to backend scan endpoint, replace UTXO report with findings

- Add GET /api/wallet/scan endpoint that shells out to detect.py
- Add CORS config and detect.py script path to application.properties
- walletService.js now calls the real scan endpoint instead of mock
- Replace UtxoCard-based ReportScreen with FindingCard-based layout
- FindingCard: collapsible card with data-driven details panel (address groups, string lists, key-value scalars)
- VulnerabilityBadge: all 14 finding types labeled, severity lowercased, critical style added
- ReportScreen: summary bar shows findings/warnings/txs analyzed; clean banner; separate warnings section

backend/requests/wallet.http

@@ -23,6 +23,10 @@ Content-Type: application/json
 ### Get UTXOs
 GET {{baseUrl}}/api/wallet/{{analyze.response.body.$.analysisId}}/utxos
 
+### Scan descriptor
+# @name scan
+GET {{baseUrl}}/api/wallet/scan?descriptor={{descriptor}}
+
 > {%
   client.test("status is 200", function() {
     client.assert(response.status === 200, "expected 200");