feat: add price chart to simulation and unit tests

Unit tests (13 passing):
- Kline fetching and processing
- Price drop condition triggers buy
- Stop loss and take profit risk management
- Multiple positions (buy again after sell)
- Max candles limit
- Stop interruption handling

Frontend:
- SignalChart now shows price movement even before signals
- Shows candle count even with no signals
- Chart displays buy/sell markers when signals exist
- Canvas-based chart with gradient fill

Backend:
- Simulation stores klines for chart display
- Returns klines in API response
- Simplified simulation run (no periodic saving)

src/frontend/package-lock.json

@@ -7,6 +7,9 @@
 		"": {
 			"name": "frontend",
 			"version": "0.0.1",
+			"dependencies": {
+				"chart.js": "^4.5.1"
+			},
 			"devDependencies": {
 				"@sveltejs/adapter-auto": "^7.0.1",
 				"@sveltejs/kit": "^2.57.0",
@@ -101,6 +104,12 @@
 				"@jridgewell/sourcemap-codec": "^1.4.14"
 			}
 		},
+		"node_modules/@kurkle/color": {
+			"version": "0.3.4",
+			"resolved": "https://registry.npmjs.org/@kurkle/color/-/color-0.3.4.tgz",
+			"integrity": "sha512-M5UknZPHRu3DEDWoipU6sE8PdkZ6Z/S+v4dD+Ke8IaNlpdSQah50lz1KtcFBa2vsdOnwbbnxJwVM4wty6udA5w==",
+			"license": "MIT"
+		},
 		"node_modules/@napi-rs/wasm-runtime": {
 			"version": "1.1.3",
 			"resolved": "https://registry.npmjs.org/@napi-rs/wasm-runtime/-/wasm-runtime-1.1.3.tgz",
@@ -569,6 +578,18 @@
 				"node": ">= 0.4"
 			}
 		},
+		"node_modules/chart.js": {
+			"version": "4.5.1",
+			"resolved": "https://registry.npmjs.org/chart.js/-/chart.js-4.5.1.tgz",
+			"integrity": "sha512-GIjfiT9dbmHRiYi6Nl2yFCq7kkwdkp1W/lp2J99rX0yo9tgJGn3lKQATztIjb5tVtevcBtIdICNWqlq5+E8/Pw==",
+			"license": "MIT",
+			"dependencies": {
+				"@kurkle/color": "^0.3.0"
+			},
+			"engines": {
+				"pnpm": ">=8"
+			}
+		},
 		"node_modules/chokidar": {
 			"version": "4.0.3",
 			"resolved": "https://registry.npmjs.org/chokidar/-/chokidar-4.0.3.tgz",