refactor(browser): improve browser path management

Implement more robust browser executable path handling using playwright's built-in browser management. This change:
- Adds async browser path resolution
- Implements path caching in the home folder
- Removes hardcoded browser paths
- Adds httpx dependency
- Removes obsolete test result files

This change makes the browser path resolution more reliable across different platforms and environments.

pyproject.toml

@@ -36,6 +36,7 @@ dependencies = [
     "aiofiles",
     "rich>=13.9.4",
     "cssselect>=1.2.0",
+    "httpx==0.27.2",
 ]
 classifiers = [
     "Development Status :: 3 - Alpha",
@@ -77,4 +78,12 @@ packages = {find = {where = ["."], include = ["crawl4ai*"]}}
 crawl4ai = ["js_snippet/*.js"]
 
 [tool.setuptools.dynamic]
-version = {attr = "crawl4ai.__version__.__version__"}
+version = {attr = "crawl4ai.__version__.__version__"}
+
+[tool.uv.sources]
+crawl4ai = { workspace = true }
+
+[dependency-groups]
+dev = [
+    "crawl4ai",
+]