feat(slides): add workshop slides for JSR-354 Money and Currency API

Introduce complete slide deck covering:
- problem statement and limitations of double, BigDecimal, and Currency
- fundamentals of MonetaryAmount, CurrencyUnit, and Money
- arithmetic operations, rounding, formatting, and parsing
- advanced concepts: currency conversion, MonetaryOperator, MonetaryQuery, MonetaryContext
- architecture and integration topics
- hands-on exercises for all sections

Add informational slide about JSR-354, its origins, and key contributors.
Include exercise guidance, pause slide, and workshop wrap-up.

Signed-off-by: Marcus Fihlon <marcus@fihlon.swiss>

slides/package.json

@@ -0,0 +1,19 @@
+{
+  "name": "jugch-gv-2026",
+  "type": "module",
+  "private": true,
+  "scripts": {
+    "build": "slidev build",
+    "dev": "slidev --open",
+    "export": "slidev export"
+  },
+  "dependencies": {
+    "@slidev/cli": "^52.14.1",
+    "@slidev/theme-default": "latest",
+    "@slidev/theme-seriph": "latest",
+    "vue": "^3.5.29"
+  },
+  "devDependencies": {
+    "playwright-chromium": "^1.58.2"
+  }
+}