fix(amazonq): isAmazonLinux2() function incorrectly identifies regular Linux/Ubuntu in web/container env as AL2

[laileni-aws]

Problem

PR: #7270 introduced a bug where the isAmazonLinux2() function incorrectly identifies regular Linux/Ubuntu systems in web/container environments as Amazon Linux 2. This happens because:

1. The function checks os.release() for .amzn2. or .amzn2int. patterns
2. In containerized environments (like VS Code web/remote), os.release() returns the host's kernel version, not the container's OS
3. If the host is Amazon Linux 2 but the container is Ubuntu/Linux, the function incorrectly returns true
4. This prevents Amazon Q LSP from starting because it thinks it's on AL2 without the required GLIBC patch

Solution

• Skip AL2 detection for web environments - Returns false immediately since web mode runs in a browser

• Check /etc/os-release first - In containerized environments, this file contains the actual container OS, not the host OS

• Trust container OS over kernel version - If /etc/os-release shows it's not AL2 (e.g., Ubuntu), return false regardless of kernel version

• Fall back to kernel check only when necessary - Only use os.release() if we can't read /etc/os-release or if it confirms AL2

• Prioritized container OS detection over kernel version detection

• Maintained backward compatibility for actual AL2 systems

• Added comprehensive test coverage for the new scenarios

---

• Treat all work as PUBLIC. Private feature/x branches will not be squash-merged at release time.
• Your code changes must meet the guidelines in CONTRIBUTING.md.
• License: I confirm that my contribution is made under the terms of the Apache 2.0 license.

[amazon-inspector-ohio]

⏳ I'm reviewing this pull request for security vulnerabilities and code quality issues. I'll provide an update when I'm done

[amazon-inspector-ohio]

✅ I finished the code review, and didn't find any security or code quality issues.

[amazon-inspector-ohio]

⏳ I'm reviewing this pull request for security vulnerabilities and code quality issues. I'll provide an update when I'm done

[amazon-inspector-ohio]

✅ I finished the code review, and didn't find any security or code quality issues.

[murkvin]

I've left a few comments and questions.

[murkvin]

I'm wondering if we can still strip away more.