Add build commands to AGENTS.md; document CVV2/iCVV service-code forcing in card validation ops

AGENTS.md:
- Added npm start (dev server), npm run build (prod), and NODE_OPTIONS heap-size tip from upstream Getting-started wiki

Card Validation Data Generate/Verify:
- Added Profile behaviour note to both descriptions: CVV2 forces service code 000, iCVV forces 999, the arg is ignored for those profiles

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

AGENTS.md

@@ -8,6 +8,7 @@
   - Node 24
   - `npm ci`
   - `npm test`
+- Dev server with auto-rebuild: `npm start` (port 8080). Production build: `npm run build` (output in `build/prod/`). If the production build OOMs, set `NODE_OPTIONS=--max_old_space_size=2048`.
 - Do not spend time fixing Windows-only runtime or dependency issues unless explicitly requested.
 - Do not commit repo changes whose only purpose is to make local Windows execution work.
 - If a failure appears only in the local Windows shell, do not treat it as a code regression until it reproduces in Docker/Linux.

src/core/operations/GenerateCardValidationData.mjs

@@ -19,7 +19,7 @@ class GenerateCardValidationData extends Operation {
 
         this.name = "Card Validation Data Generate";
         this.module = "Payment";
-        this.description = "Paste the combined CVK pair into the input field as hex and generate a card-verification value for software testing.<br><br><b>Input:</b> combined CVK pair as 16-byte or 24-byte hex.<br><b>Arguments:</b> select whether you are generating CVV/CVC, CVV2/CVC2, or iCVV, then provide the PAN, expiry components, and service code details.<br><br>This implementation is intended for test harnesses and assumes the common CVV decimalization flow used by payment HSM integrations.";
+        this.description = "Paste the combined CVK pair into the input field as hex and generate a card-verification value for software testing.<br><br><b>Input:</b> combined CVK pair as 16-byte or 24-byte hex.<br><b>Arguments:</b> select whether you are generating CVV/CVC, CVV2/CVC2, or iCVV, then provide the PAN, expiry components, and service code details.<br><br><b>Profile behaviour:</b> CVV2/CVC2 forces service code <code>000</code> regardless of the supplied service code. iCVV forces service code <code>999</code>. CVV/CVC uses the supplied service code directly.<br><br>This implementation is intended for test harnesses and assumes the common CVV decimalization flow used by payment HSM integrations.";
         this.inlineHelp = "<strong>Input:</strong> combined CVK pair hex.<br><strong>Args:</strong> choose the validation-data profile, then provide PAN, expiry, and service-code inputs.";
         this.testDataSamples = [
             {

src/core/operations/VerifyCardValidationData.mjs

@@ -19,7 +19,7 @@ class VerifyCardValidationData extends Operation {
 
         this.name = "Card Validation Data Verify";
         this.module = "Payment";
-        this.description = "Paste the combined CVK pair into the input field as hex and verify a CVV/CVC-style value for software testing.<br><br><b>Input:</b> combined CVK pair as 16-byte or 24-byte hex.<br><b>Arguments:</b> select the validation-data profile, provide the PAN and expiry components, then supply the expected validation data.<br><br>This operation recomputes the validation value using the same assumptions as the generate operation and reports whether the supplied value matches.";
+        this.description = "Paste the combined CVK pair into the input field as hex and verify a CVV/CVC-style value for software testing.<br><br><b>Input:</b> combined CVK pair as 16-byte or 24-byte hex.<br><b>Arguments:</b> select the validation-data profile, provide the PAN and expiry components, then supply the expected validation data.<br><br><b>Profile behaviour:</b> CVV2/CVC2 forces service code <code>000</code> and iCVV forces <code>999</code> — the service code arg is ignored for those profiles.<br><br>This operation recomputes the validation value using the same assumptions as the generate operation and reports whether the supplied value matches.";
         this.inlineHelp = "<strong>Input:</strong> combined CVK pair hex.<br><strong>Args:</strong> provide PAN, expiry, service-code context, and the validation data to check.";
         this.testDataSamples = [
             {