Create multitenant_memory_manager.go (closes #206)

[RAPIDENN]

This commit implements the proposal from issue #206.

• Solves:
  • Memory leak in Codeium #63: memory leak (by enforcing per-namespace memory caps and LRU-based cleanup)
  • Windsurf Language Server Crashes with "Too Many Open Files" Error #176: too many open files (by scoping resource usage to user/project namespaces)
  • #431: progressive memory growth (fixed via session expiration logic)
  • Language server doesn't stop after VS Code is closed #5: zombie processes after IDE shutdown (cleaned up via session lifecycle control)

Implements per-user and per-project namespace isolation with memory limits, LRU eviction, and automatic cleanup after inactivity.

This change addresses a class of long-standing issues caused by unscoped memory and file descriptor usage in multi-session environments. It also prevents known edge cases such as hitting the 1024 FD limit in glibc’s select() implementation—an issue widely discussed by developers due to how it silently breaks applications when the descriptor count exceeds the hardcoded FD_SETSIZE. These bugs are notoriously difficult to trace and have led to crashes, corrupted state, and even exploitation in CTF challenges.

The new memory manager integrates with the language server via a LanguageServerExtension and requires minimal changes to the surrounding codebase. It improves scalability, stability, and memory safety in high-concurrency environments by ensuring each user/project session operates independently with enforced limits.

Extended Impact & Methodology Report
https://pdf-bjvf.vercel.app/impact207.html

[androidacy-user]

hope this gets merged soon! codeium/windsurf will randomly start using 12gb of ram on my machine - and i only have 32 :)

[RAPIDENN]

Thanks a lot for confirming the issue, @androidacy-user!
If possible, could you share a screenshot showing both the high memory usage and your total system RAM (e.g. 32GB)? That would really help validate the problem for reviewers and show why PR #207 is crucial.

Appreciate it. Even a quick Task Manager or htop shot helps!

[androidacy-user]

Thanks a lot for confirming the issue, @androidacy-user! If possible, could you share a screenshot showing both the high memory usage and your total system RAM (e.g. 32GB)? That would really help validate the problem for reviewers and show why PR #207 is crucial.

Appreciate it. Even a quick Task Manager or htop shot helps!

not quite at 12gb right now, it happens randomly, but here is AS using about 1gb more than without windsurf, plus >2gb for the code server (plus a couple hundred mb for JCEF but thats negligible on my system). usually when it happens AS and cascade both become quite laggy though.