Tasks: add watch mode (#845)

```
pnpm install
cd pacakges/tasks
pnpm run watch
```

cc @coyotte508 when you're back

Author: krampstudio

package.json

@@ -17,6 +17,7 @@
 		"eslint-config-prettier": "^9.0.0",
 		"eslint-plugin-prettier": "^4.2.1",
 		"eslint-plugin-svelte": "^2.30.0",
+		"npm-run-all": "^4.1.5",
 		"prettier": "^3.1.0",
 		"prettier-plugin-svelte": "^3.1.2",
 		"semver": "^7.5.0",

packages/tasks/package.json

@@ -25,6 +25,9 @@
 		"format:check": "prettier --check .",
 		"prepublishOnly": "pnpm run inference-codegen && git diff --name-only --exit-code src && pnpm run build",
 		"build": "tsup src/index.ts --format cjs,esm --clean && tsc --emitDeclarationOnly --declaration",
+		"watch:export": "tsup src/index.ts --format cjs,esm --watch",
+		"watch:types": "tsc --emitDeclarationOnly --declaration --watch",
+		"watch": "npm-run-all --parallel watch:export watch:types",
 		"prepare": "pnpm run build",
 		"check": "tsc",
 		"inference-codegen": "tsx scripts/inference-codegen.ts && prettier --write src/tasks/*/inference.ts",