ci: Add test:unit scripts so AI/Utils coverage is uploaded (#31170)

Co-authored-by: n8n-cat-bot[bot] <n8n-cat-bot[bot]@users.noreply.github.com>
Co-authored-by: Declan Carroll <declan@n8n.io>
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/@n8n/agents/package.json

@@ -20,6 +20,7 @@
       "types": "./dist/index.d.ts",
       "default": "./dist/index.js"
     },
+    "./package.json": "./package.json",
     "./tool": {
       "types": "./dist/sdk/tool.d.ts",
       "default": "./dist/sdk/tool.js"

packages/@n8n/instance-ai/package.json

@@ -8,6 +8,7 @@
     "format": "biome format --write src",
     "format:check": "biome ci src",
     "test": "jest",
+    "test:unit": "jest",
     "lint": "eslint . --quiet",
     "lint:fix": "eslint . --fix",
     "eval:instance-ai": "tsx evaluations/cli/index.ts",

packages/@n8n/mcp-browser-extension/package.json

@@ -11,6 +11,7 @@
 		"lint": "eslint . --quiet",
 		"lint:fix": "eslint . --fix",
 		"test": "vitest run",
+		"test:unit": "vitest run",
 		"test:dev": "vitest",
 		"format": "biome format --write src",
 		"format:check": "biome ci src"