Fix #846: Add RAM to environment summary

[abdulrahmanhossam]

Resolves #846.

This PR adds the total physical memory (RAM) to the environment summary, appending it directly to the CPU information line to keep the summary compact and readable.

Implementation details:

• Windows: Uses GlobalMemoryStatusEx via P/Invoke.
• Linux: Reads MemTotal from /proc/meminfo.
• macOS: Uses sysctl -n hw.memsize process output.

The total memory is formatted in GB (e.g., 16 GB RAM). I used Lazy<T> to ensure the OS is only queried once and doesn't impact performance.

Let me know if any adjustments are needed!

[timcassell]

RAM is not part of the CPU technically. Just make it a new line (yield return it separately). Also, if the info is available, it could be useful to include the frequency of the RAM, and type (DDR4/5).

[timcassell]

Also free or used memory if possible (see #847 convo regarding it).

[abdulrahmanhossam]

thanks for the lightning-fast review!

1. You are absolutely right, it makes much more sense on a separate line. I will update this right away.
2. I will also update the implementation to include the Available/Free memory alongside the Total memory as discussed in the Added Memory Information - Free and Total memory for different platforms #847 thread.
3. Regarding the RAM Frequency and Type (DDR4/5): Gathering this accurately cross-platform natively in C# is quite complex without external dependencies (e.g., parsing dmidecode on Linux often requires sudo, and system_profiler on macOS is quite heavy). Would it be acceptable to scope this PR to Total/Available memory first, and perhaps track the hardware details (Frequency/Type) in a separate future issue?

Let me know if this sounds like a good plan, and I'll push the updates shortly!

[timcassell]

Doing a separate issue/PR for those is ok. Thanks @abdulrahmanhossam