feat(09-01): configure Vitest with multi-project setup

- Install Vitest, @vitest/browser, vitest-browser-svelte, @vitest/coverage-v8
- Configure multi-project: client (browser/Playwright) and server (node)
- Add test scripts: test, test:unit, test:unit:watch, test:coverage
- Coverage provider: v8 with autoUpdate thresholds

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

package-lock.json

@@ -28,6 +28,9 @@
 				"@sveltejs/kit": "^2.50.1",
 				"@sveltejs/vite-plugin-svelte": "^6.2.4",
 				"@types/better-sqlite3": "^7.6.13",
+				"@vitest/browser": "^4.0.18",
+				"@vitest/browser-playwright": "^4.0.18",
+				"@vitest/coverage-v8": "^4.0.18",
 				"drizzle-kit": "^0.31.8",
 				"eslint": "^9.39.2",
 				"eslint-config-prettier": "^10.1.8",
@@ -36,7 +39,69 @@
 				"svelte": "^5.48.2",
 				"svelte-check": "^4.3.5",
 				"typescript": "^5.9.3",
-				"vite": "^7.3.1"
+				"vite": "^7.3.1",
+				"vitest": "^4.0.18",
+				"vitest-browser-svelte": "^2.0.2"
+			}
+		},
+		"node_modules/@babel/helper-string-parser": {
+			"version": "7.27.1",
+			"resolved": "https://registry.npmjs.org/@babel/helper-string-parser/-/helper-string-parser-7.27.1.tgz",
+			"integrity": "sha512-qMlSxKbpRlAridDExk92nSobyDdpPijUq2DW6oDnUqd0iOGxmQjyqhMIihI9+zv4LPyZdRje2cavWPbCbWm3eA==",
+			"dev": true,
+			"license": "MIT",
+			"engines": {
+				"node": ">=6.9.0"
+			}
+		},
+		"node_modules/@babel/helper-validator-identifier": {
+			"version": "7.28.5",
+			"resolved": "https://registry.npmjs.org/@babel/helper-validator-identifier/-/helper-validator-identifier-7.28.5.tgz",
+			"integrity": "sha512-qSs4ifwzKJSV39ucNjsvc6WVHs6b7S03sOh2OcHF9UHfVPqWWALUsNUVzhSBiItjRZoLHx7nIarVjqKVusUZ1Q==",
+			"dev": true,
+			"license": "MIT",
+			"engines": {
+				"node": ">=6.9.0"
+			}
+		},
+		"node_modules/@babel/parser": {
+			"version": "7.29.0",
+			"resolved": "https://registry.npmjs.org/@babel/parser/-/parser-7.29.0.tgz",
+			"integrity": "sha512-IyDgFV5GeDUVX4YdF/3CPULtVGSXXMLh1xVIgdCgxApktqnQV0r7/8Nqthg+8YLGaAtdyIlo2qIdZrbCv4+7ww==",
+			"dev": true,
+			"license": "MIT",
+			"dependencies": {
+				"@babel/types": "^7.29.0"
+			},
+			"bin": {
+				"parser": "bin/babel-parser.js"
+			},
+			"engines": {
+				"node": ">=6.0.0"
+			}
+		},
+		"node_modules/@babel/types": {
+			"version": "7.29.0",
+			"resolved": "https://registry.npmjs.org/@babel/types/-/types-7.29.0.tgz",
+			"integrity": "sha512-LwdZHpScM4Qz8Xw2iKSzS+cfglZzJGvofQICy7W7v4caru4EaAmyUuO6BGrbyQ2mYV11W0U8j5mBhd14dd3B0A==",
+			"dev": true,
+			"license": "MIT",
+			"dependencies": {
+				"@babel/helper-string-parser": "^7.27.1",
+				"@babel/helper-validator-identifier": "^7.28.5"
+			},
+			"engines": {
+				"node": ">=6.9.0"
+			}
+		},
+		"node_modules/@bcoe/v8-coverage": {
+			"version": "1.0.2",
+			"resolved": "https://registry.npmjs.org/@bcoe/v8-coverage/-/v8-coverage-1.0.2.tgz",
+			"integrity": "sha512-6zABk/ECA/QYSCQ1NGiVwwbQerUCZ+TQbp64Q3AgmfNvurHH0j8TtXa1qbShXA6qqkpAj4V5W8pP6mLe1mcMqA==",
+			"dev": true,
+			"license": "MIT",
+			"engines": {
+				"node": ">=18"
 			}
 		},
 		"node_modules/@drizzle-team/brocli": {
@@ -2471,6 +2536,19 @@
 				"vite": "^5.2.0 || ^6 || ^7"
 			}
 		},
+		"node_modules/@testing-library/svelte-core": {
+			"version": "1.0.0",
+			"resolved": "https://registry.npmjs.org/@testing-library/svelte-core/-/svelte-core-1.0.0.tgz",
+			"integrity": "sha512-VkUePoLV6oOYwSUvX6ShA8KLnJqZiYMIbP2JW2t0GLWLkJxKGvuH5qrrZBV/X7cXFnLGuFQEC7RheYiZOW68KQ==",
+			"dev": true,
+			"license": "MIT",
+			"engines": {
+				"node": ">=16"
+			},
+			"peerDependencies": {
+				"svelte": "^3 || ^4 || ^5 || ^5.0.0-next.0"
+			}
+		},
 		"node_modules/@types/better-sqlite3": {
 			"version": "7.6.13",
 			"resolved": "https://registry.npmjs.org/@types/better-sqlite3/-/better-sqlite3-7.6.13.tgz",
@@ -2481,6 +2559,17 @@
 				"@types/node": "*"
 			}
 		},
+		"node_modules/@types/chai": {
+			"version": "5.2.3",
+			"resolved": "https://registry.npmjs.org/@types/chai/-/chai-5.2.3.tgz",
+			"integrity": "sha512-Mw558oeA9fFbv65/y4mHtXDs9bPnFMZAL/jxdPFUpOHHIXX91mcgEHbS5Lahr+pwZFR8A7GQleRWeI6cGFC2UA==",
+			"dev": true,
+			"license": "MIT",
+			"dependencies": {
+				"@types/deep-eql": "*",
+				"assertion-error": "^2.0.1"
+			}
+		},
 		"node_modules/@types/cookie": {
 			"version": "0.6.0",
 			"resolved": "https://registry.npmjs.org/@types/cookie/-/cookie-0.6.0.tgz",
@@ -2488,6 +2577,13 @@
 			"dev": true,
 			"license": "MIT"
 		},
+		"node_modules/@types/deep-eql": {
+			"version": "4.0.2",
+			"resolved": "https://registry.npmjs.org/@types/deep-eql/-/deep-eql-4.0.2.tgz",
+			"integrity": "sha512-c9h9dVVMigMPc4bwTvC5dxqtqJZwQPePsWjPlpSOnojbor6pGqdk541lfA7AqFQr5pB1BRdq0juY9db81BwyFw==",
+			"dev": true,
+			"license": "MIT"
+		},
 		"node_modules/@types/estree": {
 			"version": "1.0.8",
 			"resolved": "https://registry.npmjs.org/@types/estree/-/estree-1.0.8.tgz",
@@ -2518,6 +2614,205 @@
 			"dev": true,
 			"license": "MIT"
 		},
+		"node_modules/@vitest/browser": {
+			"version": "4.0.18",
+			"resolved": "https://registry.npmjs.org/@vitest/browser/-/browser-4.0.18.tgz",
+			"integrity": "sha512-gVQqh7paBz3gC+ZdcCmNSWJMk70IUjDeVqi+5m5vYpEHsIwRgw3Y545jljtajhkekIpIp5Gg8oK7bctgY0E2Ng==",
+			"dev": true,
+			"license": "MIT",
+			"dependencies": {
+				"@vitest/mocker": "4.0.18",
+				"@vitest/utils": "4.0.18",
+				"magic-string": "^0.30.21",
+				"pixelmatch": "7.1.0",
+				"pngjs": "^7.0.0",
+				"sirv": "^3.0.2",
+				"tinyrainbow": "^3.0.3",
+				"ws": "^8.18.3"
+			},
+			"funding": {
+				"url": "https://opencollective.com/vitest"
+			},
+			"peerDependencies": {
+				"vitest": "4.0.18"
+			}
+		},
+		"node_modules/@vitest/browser-playwright": {
+			"version": "4.0.18",
+			"resolved": "https://registry.npmjs.org/@vitest/browser-playwright/-/browser-playwright-4.0.18.tgz",
+			"integrity": "sha512-gfajTHVCiwpxRj1qh0Sh/5bbGLG4F/ZH/V9xvFVoFddpITfMta9YGow0W6ZpTTORv2vdJuz9TnrNSmjKvpOf4g==",
+			"dev": true,
+			"license": "MIT",
+			"dependencies": {
+				"@vitest/browser": "4.0.18",
+				"@vitest/mocker": "4.0.18",
+				"tinyrainbow": "^3.0.3"
+			},
+			"funding": {
+				"url": "https://opencollective.com/vitest"
+			},
+			"peerDependencies": {
+				"playwright": "*",
+				"vitest": "4.0.18"
+			},
+			"peerDependenciesMeta": {
+				"playwright": {
+					"optional": false
+				}
+			}
+		},
+		"node_modules/@vitest/coverage-v8": {
+			"version": "4.0.18",
+			"resolved": "https://registry.npmjs.org/@vitest/coverage-v8/-/coverage-v8-4.0.18.tgz",
+			"integrity": "sha512-7i+N2i0+ME+2JFZhfuz7Tg/FqKtilHjGyGvoHYQ6iLV0zahbsJ9sljC9OcFcPDbhYKCet+sG8SsVqlyGvPflZg==",
+			"dev": true,
+			"license": "MIT",
+			"dependencies": {
+				"@bcoe/v8-coverage": "^1.0.2",
+				"@vitest/utils": "4.0.18",
+				"ast-v8-to-istanbul": "^0.3.10",
+				"istanbul-lib-coverage": "^3.2.2",
+				"istanbul-lib-report": "^3.0.1",
+				"istanbul-reports": "^3.2.0",
+				"magicast": "^0.5.1",
+				"obug": "^2.1.1",
+				"std-env": "^3.10.0",
+				"tinyrainbow": "^3.0.3"
+			},
+			"funding": {
+				"url": "https://opencollective.com/vitest"
+			},
+			"peerDependencies": {
+				"@vitest/browser": "4.0.18",
+				"vitest": "4.0.18"
+			},
+			"peerDependenciesMeta": {
+				"@vitest/browser": {
+					"optional": true
+				}
+			}
+		},
+		"node_modules/@vitest/expect": {
+			"version": "4.0.18",
+			"resolved": "https://registry.npmjs.org/@vitest/expect/-/expect-4.0.18.tgz",
+			"integrity": "sha512-8sCWUyckXXYvx4opfzVY03EOiYVxyNrHS5QxX3DAIi5dpJAAkyJezHCP77VMX4HKA2LDT/Jpfo8i2r5BE3GnQQ==",
+			"dev": true,
+			"license": "MIT",
+			"dependencies": {
+				"@standard-schema/spec": "^1.0.0",
+				"@types/chai": "^5.2.2",
+				"@vitest/spy": "4.0.18",
+				"@vitest/utils": "4.0.18",
+				"chai": "^6.2.1",
+				"tinyrainbow": "^3.0.3"
+			},
+			"funding": {
+				"url": "https://opencollective.com/vitest"
+			}
+		},
+		"node_modules/@vitest/mocker": {
+			"version": "4.0.18",
+			"resolved": "https://registry.npmjs.org/@vitest/mocker/-/mocker-4.0.18.tgz",
+			"integrity": "sha512-HhVd0MDnzzsgevnOWCBj5Otnzobjy5wLBe4EdeeFGv8luMsGcYqDuFRMcttKWZA5vVO8RFjexVovXvAM4JoJDQ==",
+			"dev": true,
+			"license": "MIT",
+			"dependencies": {
+				"@vitest/spy": "4.0.18",
+				"estree-walker": "^3.0.3",
+				"magic-string": "^0.30.21"
+			},
+			"funding": {
+				"url": "https://opencollective.com/vitest"
+			},
+			"peerDependencies": {
+				"msw": "^2.4.9",
+				"vite": "^6.0.0 || ^7.0.0-0"
+			},
+			"peerDependenciesMeta": {
+				"msw": {
+					"optional": true
+				},
+				"vite": {
+					"optional": true
+				}
+			}
+		},
+		"node_modules/@vitest/mocker/node_modules/estree-walker": {
+			"version": "3.0.3",
+			"resolved": "https://registry.npmjs.org/estree-walker/-/estree-walker-3.0.3.tgz",
+			"integrity": "sha512-7RUKfXgSMMkzt6ZuXmqapOurLGPPfgj6l9uRZ7lRGolvk0y2yocc35LdcxKC5PQZdn2DMqioAQ2NoWcrTKmm6g==",
+			"dev": true,
+			"license": "MIT",
+			"dependencies": {
+				"@types/estree": "^1.0.0"
+			}
+		},
+		"node_modules/@vitest/pretty-format": {
+			"version": "4.0.18",
+			"resolved": "https://registry.npmjs.org/@vitest/pretty-format/-/pretty-format-4.0.18.tgz",
+			"integrity": "sha512-P24GK3GulZWC5tz87ux0m8OADrQIUVDPIjjj65vBXYG17ZeU3qD7r+MNZ1RNv4l8CGU2vtTRqixrOi9fYk/yKw==",
+			"dev": true,
+			"license": "MIT",
+			"dependencies": {
+				"tinyrainbow": "^3.0.3"
+			},
+			"funding": {
+				"url": "https://opencollective.com/vitest"
+			}
+		},
+		"node_modules/@vitest/runner": {
+			"version": "4.0.18",
+			"resolved": "https://registry.npmjs.org/@vitest/runner/-/runner-4.0.18.tgz",
+			"integrity": "sha512-rpk9y12PGa22Jg6g5M3UVVnTS7+zycIGk9ZNGN+m6tZHKQb7jrP7/77WfZy13Y/EUDd52NDsLRQhYKtv7XfPQw==",
+			"dev": true,
+			"license": "MIT",
+			"dependencies": {
+				"@vitest/utils": "4.0.18",
+				"pathe": "^2.0.3"
+			},
+			"funding": {
+				"url": "https://opencollective.com/vitest"
+			}
+		},
+		"node_modules/@vitest/snapshot": {
+			"version": "4.0.18",
+			"resolved": "https://registry.npmjs.org/@vitest/snapshot/-/snapshot-4.0.18.tgz",
+			"integrity": "sha512-PCiV0rcl7jKQjbgYqjtakly6T1uwv/5BQ9SwBLekVg/EaYeQFPiXcgrC2Y7vDMA8dM1SUEAEV82kgSQIlXNMvA==",
+			"dev": true,
+			"license": "MIT",
+			"dependencies": {
+				"@vitest/pretty-format": "4.0.18",
+				"magic-string": "^0.30.21",
+				"pathe": "^2.0.3"
+			},
+			"funding": {
+				"url": "https://opencollective.com/vitest"
+			}
+		},
+		"node_modules/@vitest/spy": {
+			"version": "4.0.18",
+			"resolved": "https://registry.npmjs.org/@vitest/spy/-/spy-4.0.18.tgz",
+			"integrity": "sha512-cbQt3PTSD7P2OARdVW3qWER5EGq7PHlvE+QfzSC0lbwO+xnt7+XH06ZzFjFRgzUX//JmpxrCu92VdwvEPlWSNw==",
+			"dev": true,
+			"license": "MIT",
+			"funding": {
+				"url": "https://opencollective.com/vitest"
+			}
+		},
+		"node_modules/@vitest/utils": {
+			"version": "4.0.18",
+			"resolved": "https://registry.npmjs.org/@vitest/utils/-/utils-4.0.18.tgz",
+			"integrity": "sha512-msMRKLMVLWygpK3u2Hybgi4MNjcYJvwTb0Ru09+fOyCXIgT5raYP041DRRdiJiI3k/2U6SEbAETB3YtBrUkCFA==",
+			"dev": true,
+			"license": "MIT",
+			"dependencies": {
+				"@vitest/pretty-format": "4.0.18",
+				"tinyrainbow": "^3.0.3"
+			},
+			"funding": {
+				"url": "https://opencollective.com/vitest"
+			}
+		},
 		"node_modules/acorn": {
 			"version": "8.15.0",
 			"resolved": "https://registry.npmjs.org/acorn/-/acorn-8.15.0.tgz",
@@ -2589,6 +2884,38 @@
 				"node": ">= 0.4"
 			}
 		},
+		"node_modules/assertion-error": {
+			"version": "2.0.1",
+			"resolved": "https://registry.npmjs.org/assertion-error/-/assertion-error-2.0.1.tgz",
+			"integrity": "sha512-Izi8RQcffqCeNVgFigKli1ssklIbpHnCYc6AknXGYoB6grJqyeby7jv12JUQgmTAnIDnbck1uxksT4dzN3PWBA==",
+			"dev": true,
+			"license": "MIT",
+			"engines": {
+				"node": ">=12"
+			}
+		},
+		"node_modules/ast-v8-to-istanbul": {
+			"version": "0.3.11",
+			"resolved": "https://registry.npmjs.org/ast-v8-to-istanbul/-/ast-v8-to-istanbul-0.3.11.tgz",
+			"integrity": "sha512-Qya9fkoofMjCBNVdWINMjB5KZvkYfaO9/anwkWnjxibpWUxo5iHl2sOdP7/uAqaRuUYuoo8rDwnbaaKVFxoUvw==",
+			"dev": true,
+			"license": "MIT",
+			"dependencies": {
+				"@jridgewell/trace-mapping": "^0.3.31",
+				"estree-walker": "^3.0.3",
+				"js-tokens": "^10.0.0"
+			}
+		},
+		"node_modules/ast-v8-to-istanbul/node_modules/estree-walker": {
+			"version": "3.0.3",
+			"resolved": "https://registry.npmjs.org/estree-walker/-/estree-walker-3.0.3.tgz",
+			"integrity": "sha512-7RUKfXgSMMkzt6ZuXmqapOurLGPPfgj6l9uRZ7lRGolvk0y2yocc35LdcxKC5PQZdn2DMqioAQ2NoWcrTKmm6g==",
+			"dev": true,
+			"license": "MIT",
+			"dependencies": {
+				"@types/estree": "^1.0.0"
+			}
+		},
 		"node_modules/axobject-query": {
 			"version": "4.1.0",
 			"resolved": "https://registry.npmjs.org/axobject-query/-/axobject-query-4.1.0.tgz",
@@ -2717,6 +3044,16 @@
 				"node": ">=6"
 			}
 		},
+		"node_modules/chai": {
+			"version": "6.2.2",
+			"resolved": "https://registry.npmjs.org/chai/-/chai-6.2.2.tgz",
+			"integrity": "sha512-NUPRluOfOiTKBKvWPtSD4PhFvWCqOi0BGStNWs57X9js7XGTprSmFoz5F0tWhR4WPjNeR9jXqdC7/UpSJTnlRg==",
+			"dev": true,
+			"license": "MIT",
+			"engines": {
+				"node": ">=18"
+			}
+		},
 		"node_modules/chalk": {
 			"version": "4.1.2",
 			"resolved": "https://registry.npmjs.org/chalk/-/chalk-4.1.2.tgz",
@@ -3558,6 +3895,13 @@
 				"node": ">=10.13.0"
 			}
 		},
+		"node_modules/es-module-lexer": {
+			"version": "1.7.0",
+			"resolved": "https://registry.npmjs.org/es-module-lexer/-/es-module-lexer-1.7.0.tgz",
+			"integrity": "sha512-jEQoCwk8hyb2AZziIOLhDqpm5+2ww5uIE6lkO/6jcOCusfk6LhMHpXXfBLXTZ7Ydyt0j4VoUQv6uGNYbdW+kBA==",
+			"dev": true,
+			"license": "MIT"
+		},
 		"node_modules/esbuild": {
 			"version": "0.27.2",
 			"resolved": "https://registry.npmjs.org/esbuild/-/esbuild-0.27.2.tgz",
@@ -3873,6 +4217,16 @@
 				"node": ">=6"
 			}
 		},
+		"node_modules/expect-type": {
+			"version": "1.3.0",
+			"resolved": "https://registry.npmjs.org/expect-type/-/expect-type-1.3.0.tgz",
+			"integrity": "sha512-knvyeauYhqjOYvQ66MznSMs83wmHrCycNEN6Ao+2AeYEfxUIkuiVxdEa1qlGEPK+We3n0THiDciYSsCcgW/DoA==",
+			"dev": true,
+			"license": "Apache-2.0",
+			"engines": {
+				"node": ">=12.0.0"
+			}
+		},
 		"node_modules/fast-deep-equal": {
 			"version": "3.1.3",
 			"resolved": "https://registry.npmjs.org/fast-deep-equal/-/fast-deep-equal-3.1.3.tgz",
@@ -4072,6 +4426,13 @@
 				"node": ">= 0.4"
 			}
 		},
+		"node_modules/html-escaper": {
+			"version": "2.0.2",
+			"resolved": "https://registry.npmjs.org/html-escaper/-/html-escaper-2.0.2.tgz",
+			"integrity": "sha512-H2iMtd0I4Mt5eYiapRdIDjp+XzelXQ0tFE4JS7YFwFevXXMmOp9myNrUvCg0D6ws8iqkRPBfKHgbwig1SmlLfg==",
+			"dev": true,
+			"license": "MIT"
+		},
 		"node_modules/ieee754": {
 			"version": "1.2.1",
 			"resolved": "https://registry.npmjs.org/ieee754/-/ieee754-1.2.1.tgz",
@@ -4203,6 +4564,45 @@
 			"dev": true,
 			"license": "ISC"
 		},
+		"node_modules/istanbul-lib-coverage": {
+			"version": "3.2.2",
+			"resolved": "https://registry.npmjs.org/istanbul-lib-coverage/-/istanbul-lib-coverage-3.2.2.tgz",
+			"integrity": "sha512-O8dpsF+r0WV/8MNRKfnmrtCWhuKjxrq2w+jpzBL5UZKTi2LeVWnWOmWRxFlesJONmc+wLAGvKQZEOanko0LFTg==",
+			"dev": true,
+			"license": "BSD-3-Clause",
+			"engines": {
+				"node": ">=8"
+			}
+		},
+		"node_modules/istanbul-lib-report": {
+			"version": "3.0.1",
+			"resolved": "https://registry.npmjs.org/istanbul-lib-report/-/istanbul-lib-report-3.0.1.tgz",
+			"integrity": "sha512-GCfE1mtsHGOELCU8e/Z7YWzpmybrx/+dSTfLrvY8qRmaY6zXTKWn6WQIjaAFw069icm6GVMNkgu0NzI4iPZUNw==",
+			"dev": true,
+			"license": "BSD-3-Clause",
+			"dependencies": {
+				"istanbul-lib-coverage": "^3.0.0",
+				"make-dir": "^4.0.0",
+				"supports-color": "^7.1.0"
+			},
+			"engines": {
+				"node": ">=10"
+			}
+		},
+		"node_modules/istanbul-reports": {
+			"version": "3.2.0",
+			"resolved": "https://registry.npmjs.org/istanbul-reports/-/istanbul-reports-3.2.0.tgz",
+			"integrity": "sha512-HGYWWS/ehqTV3xN10i23tkPkpH46MLCIMFNCaaKNavAXTF1RkqxawEPtnjnGZ6XKSInBKkiOA5BKS+aZiY3AvA==",
+			"dev": true,
+			"license": "BSD-3-Clause",
+			"dependencies": {
+				"html-escaper": "^2.0.0",
+				"istanbul-lib-report": "^3.0.0"
+			},
+			"engines": {
+				"node": ">=8"
+			}
+		},
 		"node_modules/jiti": {
 			"version": "2.6.1",
 			"resolved": "https://registry.npmjs.org/jiti/-/jiti-2.6.1.tgz",
@@ -4212,6 +4612,13 @@
 				"jiti": "lib/jiti-cli.mjs"
 			}
 		},
+		"node_modules/js-tokens": {
+			"version": "10.0.0",
+			"resolved": "https://registry.npmjs.org/js-tokens/-/js-tokens-10.0.0.tgz",
+			"integrity": "sha512-lM/UBzQmfJRo9ABXbPWemivdCW8V2G8FHaHdypQaIy523snUjog0W71ayWXTjiR+ixeMyVHN2XcpnTd/liPg/Q==",
+			"dev": true,
+			"license": "MIT"
+		},
 		"node_modules/js-yaml": {
 			"version": "4.1.1",
 			"resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-4.1.1.tgz",
@@ -4584,6 +4991,34 @@
 				"@jridgewell/sourcemap-codec": "^1.5.5"
 			}
 		},
+		"node_modules/magicast": {
+			"version": "0.5.1",
+			"resolved": "https://registry.npmjs.org/magicast/-/magicast-0.5.1.tgz",
+			"integrity": "sha512-xrHS24IxaLrvuo613F719wvOIv9xPHFWQHuvGUBmPnCA/3MQxKI3b+r7n1jAoDHmsbC5bRhTZYR77invLAxVnw==",
+			"dev": true,
+			"license": "MIT",
+			"dependencies": {
+				"@babel/parser": "^7.28.5",
+				"@babel/types": "^7.28.5",
+				"source-map-js": "^1.2.1"
+			}
+		},
+		"node_modules/make-dir": {
+			"version": "4.0.0",
+			"resolved": "https://registry.npmjs.org/make-dir/-/make-dir-4.0.0.tgz",
+			"integrity": "sha512-hXdUTZYIVOt1Ex//jAQi+wTZZpUpwBj/0QsOzqegb3rGMMeJiSEu5xLHnYfBrRV4RH2+OCSOO95Is/7x1WJ4bw==",
+			"dev": true,
+			"license": "MIT",
+			"dependencies": {
+				"semver": "^7.5.3"
+			},
+			"engines": {
+				"node": ">=10"
+			},
+			"funding": {
+				"url": "https://github.com/sponsors/sindresorhus"
+			}
+		},
 		"node_modules/mimic-response": {
 			"version": "3.1.0",
 			"resolved": "https://registry.npmjs.org/mimic-response/-/mimic-response-3.1.0.tgz",
@@ -4804,6 +5239,13 @@
 			"dev": true,
 			"license": "MIT"
 		},
+		"node_modules/pathe": {
+			"version": "2.0.3",
+			"resolved": "https://registry.npmjs.org/pathe/-/pathe-2.0.3.tgz",
+			"integrity": "sha512-WUjGcAqP1gQacoQe+OBJsFA7Ld4DyXuUIjZ5cc75cLHvJ7dtNsTugphxIADwspS+AraAUePCKrSVtPLFj/F88w==",
+			"dev": true,
+			"license": "MIT"
+		},
 		"node_modules/picocolors": {
 			"version": "1.1.1",
 			"resolved": "https://registry.npmjs.org/picocolors/-/picocolors-1.1.1.tgz",
@@ -4822,6 +5264,19 @@
 				"url": "https://github.com/sponsors/jonschlinkert"
 			}
 		},
+		"node_modules/pixelmatch": {
+			"version": "7.1.0",
+			"resolved": "https://registry.npmjs.org/pixelmatch/-/pixelmatch-7.1.0.tgz",
+			"integrity": "sha512-1wrVzJ2STrpmONHKBy228LM1b84msXDUoAzVEl0R8Mz4Ce6EPr+IVtxm8+yvrqLYMHswREkjYFaMxnyGnaY3Ng==",
+			"dev": true,
+			"license": "ISC",
+			"dependencies": {
+				"pngjs": "^7.0.0"
+			},
+			"bin": {
+				"pixelmatch": "bin/pixelmatch"
+			}
+		},
 		"node_modules/playwright": {
 			"version": "1.58.1",
 			"resolved": "https://registry.npmjs.org/playwright/-/playwright-1.58.1.tgz",
@@ -4869,6 +5324,16 @@
 				"node": "^8.16.0 || ^10.6.0 || >=11.0.0"
 			}
 		},
+		"node_modules/pngjs": {
+			"version": "7.0.0",
+			"resolved": "https://registry.npmjs.org/pngjs/-/pngjs-7.0.0.tgz",
+			"integrity": "sha512-LKWqWJRhstyYo9pGvgor/ivk2w94eSjE3RGVuzLGlr3NmD8bf7RcYGze1mNdEHRP6TRP6rMuDHk5t44hnTRyow==",
+			"dev": true,
+			"license": "MIT",
+			"engines": {
+				"node": ">=14.19.0"
+			}
+		},
 		"node_modules/postcss": {
 			"version": "8.5.6",
 			"resolved": "https://registry.npmjs.org/postcss/-/postcss-8.5.6.tgz",
@@ -5355,6 +5820,13 @@
 				"node": ">=8"
 			}
 		},
+		"node_modules/siginfo": {
+			"version": "2.0.0",
+			"resolved": "https://registry.npmjs.org/siginfo/-/siginfo-2.0.0.tgz",
+			"integrity": "sha512-ybx0WO1/8bSBLEWXZvEd7gMW3Sn3JFlW3TvX1nREbDLRNQNaeNN8WK0meBwPdAaOI7TtRRRJn/Es1zhrrCHu7g==",
+			"dev": true,
+			"license": "ISC"
+		},
 		"node_modules/simple-concat": {
 			"version": "1.0.1",
 			"resolved": "https://registry.npmjs.org/simple-concat/-/simple-concat-1.0.1.tgz",
@@ -5445,6 +5917,20 @@
 				"source-map": "^0.6.0"
 			}
 		},
+		"node_modules/stackback": {
+			"version": "0.0.2",
+			"resolved": "https://registry.npmjs.org/stackback/-/stackback-0.0.2.tgz",
+			"integrity": "sha512-1XMJE5fQo1jGH6Y/7ebnwPOBEkIEnT4QF32d5R1+VXdXveM0IBMJt8zfaxX1P3QhVwrYe+576+jkANtSS2mBbw==",
+			"dev": true,
+			"license": "MIT"
+		},
+		"node_modules/std-env": {
+			"version": "3.10.0",
+			"resolved": "https://registry.npmjs.org/std-env/-/std-env-3.10.0.tgz",
+			"integrity": "sha512-5GS12FdOZNliM5mAOxFRg7Ir0pWz8MdpYm6AY6VPkGpbA7ZzmbzNcBJQ0GPvvyWgcY7QAhCgf9Uy89I03faLkg==",
+			"dev": true,
+			"license": "MIT"
+		},
 		"node_modules/string_decoder": {
 			"version": "1.3.0",
 			"resolved": "https://registry.npmjs.org/string_decoder/-/string_decoder-1.3.0.tgz",
@@ -5661,6 +6147,23 @@
 				"bintrees": "1.0.2"
 			}
 		},
+		"node_modules/tinybench": {
+			"version": "2.9.0",
+			"resolved": "https://registry.npmjs.org/tinybench/-/tinybench-2.9.0.tgz",
+			"integrity": "sha512-0+DUvqWMValLmha6lr4kD8iAMK1HzV0/aKnCtWb9v9641TnP/MFb7Pc2bxoxQjTXAErryXVgUOfv2YqNllqGeg==",
+			"dev": true,
+			"license": "MIT"
+		},
+		"node_modules/tinyexec": {
+			"version": "1.0.2",
+			"resolved": "https://registry.npmjs.org/tinyexec/-/tinyexec-1.0.2.tgz",
+			"integrity": "sha512-W/KYk+NFhkmsYpuHq5JykngiOCnxeVL8v8dFnqxSD8qEEdRfXk1SDM6JzNqcERbcGYj9tMrDQBYV9cjgnunFIg==",
+			"dev": true,
+			"license": "MIT",
+			"engines": {
+				"node": ">=18"
+			}
+		},
 		"node_modules/tinyglobby": {
 			"version": "0.2.15",
 			"resolved": "https://registry.npmjs.org/tinyglobby/-/tinyglobby-0.2.15.tgz",
@@ -5677,6 +6180,16 @@
 				"url": "https://github.com/sponsors/SuperchupuDev"
 			}
 		},
+		"node_modules/tinyrainbow": {
+			"version": "3.0.3",
+			"resolved": "https://registry.npmjs.org/tinyrainbow/-/tinyrainbow-3.0.3.tgz",
+			"integrity": "sha512-PSkbLUoxOFRzJYjjxHJt9xro7D+iilgMX/C9lawzVuYiIdcihh9DXmVibBe8lmcFrRi/VzlPjBxbN7rH24q8/Q==",
+			"dev": true,
+			"license": "MIT",
+			"engines": {
+				"node": ">=14.0.0"
+			}
+		},
 		"node_modules/totalist": {
 			"version": "3.0.1",
 			"resolved": "https://registry.npmjs.org/totalist/-/totalist-3.0.1.tgz",
@@ -5850,6 +6363,101 @@
 				}
 			}
 		},
+		"node_modules/vitest": {
+			"version": "4.0.18",
+			"resolved": "https://registry.npmjs.org/vitest/-/vitest-4.0.18.tgz",
+			"integrity": "sha512-hOQuK7h0FGKgBAas7v0mSAsnvrIgAvWmRFjmzpJ7SwFHH3g1k2u37JtYwOwmEKhK6ZO3v9ggDBBm0La1LCK4uQ==",
+			"dev": true,
+			"license": "MIT",
+			"dependencies": {
+				"@vitest/expect": "4.0.18",
+				"@vitest/mocker": "4.0.18",
+				"@vitest/pretty-format": "4.0.18",
+				"@vitest/runner": "4.0.18",
+				"@vitest/snapshot": "4.0.18",
+				"@vitest/spy": "4.0.18",
+				"@vitest/utils": "4.0.18",
+				"es-module-lexer": "^1.7.0",
+				"expect-type": "^1.2.2",
+				"magic-string": "^0.30.21",
+				"obug": "^2.1.1",
+				"pathe": "^2.0.3",
+				"picomatch": "^4.0.3",
+				"std-env": "^3.10.0",
+				"tinybench": "^2.9.0",
+				"tinyexec": "^1.0.2",
+				"tinyglobby": "^0.2.15",
+				"tinyrainbow": "^3.0.3",
+				"vite": "^6.0.0 || ^7.0.0",
+				"why-is-node-running": "^2.3.0"
+			},
+			"bin": {
+				"vitest": "vitest.mjs"
+			},
+			"engines": {
+				"node": "^20.0.0 || ^22.0.0 || >=24.0.0"
+			},
+			"funding": {
+				"url": "https://opencollective.com/vitest"
+			},
+			"peerDependencies": {
+				"@edge-runtime/vm": "*",
+				"@opentelemetry/api": "^1.9.0",
+				"@types/node": "^20.0.0 || ^22.0.0 || >=24.0.0",
+				"@vitest/browser-playwright": "4.0.18",
+				"@vitest/browser-preview": "4.0.18",
+				"@vitest/browser-webdriverio": "4.0.18",
+				"@vitest/ui": "4.0.18",
+				"happy-dom": "*",
+				"jsdom": "*"
+			},
+			"peerDependenciesMeta": {
+				"@edge-runtime/vm": {
+					"optional": true
+				},
+				"@opentelemetry/api": {
+					"optional": true
+				},
+				"@types/node": {
+					"optional": true
+				},
+				"@vitest/browser-playwright": {
+					"optional": true
+				},
+				"@vitest/browser-preview": {
+					"optional": true
+				},
+				"@vitest/browser-webdriverio": {
+					"optional": true
+				},
+				"@vitest/ui": {
+					"optional": true
+				},
+				"happy-dom": {
+					"optional": true
+				},
+				"jsdom": {
+					"optional": true
+				}
+			}
+		},
+		"node_modules/vitest-browser-svelte": {
+			"version": "2.0.2",
+			"resolved": "https://registry.npmjs.org/vitest-browser-svelte/-/vitest-browser-svelte-2.0.2.tgz",
+			"integrity": "sha512-OLJVYoIYflwToFIy3s41pZ9mVp6dwXfYd8IIsWoc57g8DyN3SxsNJ5GB1xWFPxLFlKM+1MPExjPxLaqdELrfRQ==",
+			"dev": true,
+			"license": "MIT",
+			"dependencies": {
+				"@testing-library/svelte-core": "^1.0.0"
+			},
+			"funding": {
+				"url": "https://opencollective.com/vitest"
+			},
+			"peerDependencies": {
+				"svelte": "^3 || ^4 || ^5 || ^5.0.0-next.0",
+				"vitest": "^4.0.0"
+			}
+		},
 		"node_modules/which": {
 			"version": "2.0.2",
 			"resolved": "https://registry.npmjs.org/which/-/which-2.0.2.tgz",
@@ -5866,6 +6474,23 @@
 				"node": ">= 8"
 			}
 		},
+		"node_modules/why-is-node-running": {
+			"version": "2.3.0",
+			"resolved": "https://registry.npmjs.org/why-is-node-running/-/why-is-node-running-2.3.0.tgz",
+			"integrity": "sha512-hUrmaWBdVDcxvYqnyh09zunKzROWjbZTiNy8dBEjkS7ehEDQibXJ7XvlmtbwuTclUiIyN+CyXQD4Vmko8fNm8w==",
+			"dev": true,
+			"license": "MIT",
+			"dependencies": {
+				"siginfo": "^2.0.0",
+				"stackback": "0.0.2"
+			},
+			"bin": {
+				"why-is-node-running": "cli.js"
+			},
+			"engines": {
+				"node": ">=8"
+			}
+		},
 		"node_modules/word-wrap": {
 			"version": "1.2.5",
 			"resolved": "https://registry.npmjs.org/word-wrap/-/word-wrap-1.2.5.tgz",
@@ -5882,6 +6507,28 @@
 			"integrity": "sha512-l4Sp/DRseor9wL6EvV2+TuQn63dMkPjZ/sp9XkghTEbV9KlPS1xUsZ3u7/IQO4wxtcFB4bgpQPRcR3QCvezPcQ==",
 			"license": "ISC"
 		},
+		"node_modules/ws": {
+			"version": "8.19.0",
+			"resolved": "https://registry.npmjs.org/ws/-/ws-8.19.0.tgz",
+			"integrity": "sha512-blAT2mjOEIi0ZzruJfIhb3nps74PRWTCz1IjglWEEpQl5XS/UNama6u2/rjFkDDouqr4L67ry+1aGIALViWjDg==",
+			"dev": true,
+			"license": "MIT",
+			"engines": {
+				"node": ">=10.0.0"
+			},
+			"peerDependencies": {
+				"bufferutil": "^4.0.1",
+				"utf-8-validate": ">=5.0.2"
+			},
+			"peerDependenciesMeta": {
+				"bufferutil": {
+					"optional": true
+				},
+				"utf-8-validate": {
+					"optional": true
+				}
+			}
+		},
 		"node_modules/yaml": {
 			"version": "2.8.2",
 			"resolved": "https://registry.npmjs.org/yaml/-/yaml-2.8.2.tgz",

package.json

@@ -14,6 +14,10 @@
 		"db:migrate": "drizzle-kit migrate",
 		"db:push": "drizzle-kit push",
 		"db:studio": "drizzle-kit studio",
+		"test": "vitest",
+		"test:unit": "vitest run",
+		"test:unit:watch": "vitest",
+		"test:coverage": "vitest run --coverage",
 		"test:e2e": "playwright test",
 		"test:e2e:docker": "BASE_URL=http://localhost:3000 playwright test tests/docker-deployment.spec.ts"
 	},
@@ -24,6 +28,9 @@
 		"@sveltejs/kit": "^2.50.1",
 		"@sveltejs/vite-plugin-svelte": "^6.2.4",
 		"@types/better-sqlite3": "^7.6.13",
+		"@vitest/browser": "^4.0.18",
+		"@vitest/browser-playwright": "^4.0.18",
+		"@vitest/coverage-v8": "^4.0.18",
 		"drizzle-kit": "^0.31.8",
 		"eslint": "^9.39.2",
 		"eslint-config-prettier": "^10.1.8",
@@ -32,7 +39,9 @@
 		"svelte": "^5.48.2",
 		"svelte-check": "^4.3.5",
 		"typescript": "^5.9.3",
-		"vite": "^7.3.1"
+		"vite": "^7.3.1",
+		"vitest": "^4.0.18",
+		"vitest-browser-svelte": "^2.0.2"
 	},
 	"dependencies": {
 		"@tailwindcss/vite": "^4.1.18",

vite.config.ts

@@ -1,7 +1,44 @@
 import { sveltekit } from '@sveltejs/kit/vite';
 import tailwindcss from '@tailwindcss/vite';
+import { playwright } from '@vitest/browser-playwright';
 import { defineConfig } from 'vite';
 
 export default defineConfig({
-	plugins: [tailwindcss(), sveltekit()]
+	plugins: [tailwindcss(), sveltekit()],
+	test: {
+		coverage: {
+			provider: 'v8',
+			reporter: ['text', 'json', 'html'],
+			include: ['src/**/*.{ts,svelte}'],
+			exclude: ['src/**/*.test.ts', 'src/**/*.spec.ts'],
+			thresholds: {
+				autoUpdate: true
+			}
+		},
+		projects: [
+			{
+				extends: true,
+				test: {
+					name: 'client',
+					testTimeout: 5000,
+					browser: {
+						enabled: true,
+						provider: playwright(),
+						instances: [{ browser: 'chromium' }]
+					},
+					include: ['src/**/*.svelte.{test,spec}.{js,ts}'],
+					setupFiles: ['./vitest-setup-client.ts']
+				}
+			},
+			{
+				extends: true,
+				test: {
+					name: 'server',
+					environment: 'node',
+					include: ['src/**/*.{test,spec}.{js,ts}'],
+					exclude: ['src/**/*.svelte.{test,spec}.{js,ts}']
+				}
+			}
+		]
+	}
 });