Fix/zig string safety

[tarun1sisodia]

Description

This PR fixes a critical bug in the MetaCall Zig port where string return types were being freed before they could be used by the caller. It introduces a Value(T) wrapper pattern that provides manual control over resource deinitialization (RAII-like), ensuring memory safety for multi-language calls.

Key Changes:

• root.zig: Added a Value(T) struct with get() and deinit() methods. Updated metacall to return this wrapper for strings while maintaining direct returns for primitive types.
• Portability: Replaced hardcoded absolute paths in build.zig and integrated.zig with repo-relative paths (../../../build and src/tests/*).
• Zig Compatibility: Fixed a reflective type check error (.Array vs .array) to support Zig 0.16.0-dev.
• Robustness: Added integrated stress tests (10,000 calls) and edge case validation for empty strings.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• Breaking change (API change for string returns)

Checklist:

• I have performed a self-review of my own code.
• My changes generate no new warnings.
• I have added tests that prove my fix is effective.
• I have tested the tests pass (zig build test --summary all).
• I have run zig fmt and followed style guidelines.

[Copilot]

Pull request overview

This PR addresses a lifetime bug in the Zig port where string return values from metacall could be freed before the caller uses them by introducing a manual-deinit wrapper for string returns, plus updates to Zig build/test portability.

Changes:

• Introduces a Value(T) wrapper and routes string return types through it to avoid premature metacall_value_destroy.
• Updates the integrated Zig test to use repo-relative loader paths and adds stress/edge-case coverage for string returns.
• Adds a build.zig for the Zig port and adjusts .gitignore for Zig cache directories.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 5 comments.

File	Description
source/ports/zig_port/src/root.zig	Adds Value(T) wrapper and changes metacall return type behavior for strings.
source/ports/zig_port/src/tests/integrated.zig	Uses relative test paths and adds stress/empty-string checks for string returns.
source/ports/zig_port/build.zig	Adds Zig build/test steps for the port (currently mis-wired as noted in comments).
source/ports/zig_port/.gitignore	Updates Zig cache ignore entry to .zig-cache.

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[tarun1sisodia]

above you can see the compiled and tests passed.

and here are the paths i defined

both images are not using hardcoded path

[viferga]

Do you think it's ready to merge then? I would like to add CI even if it's after this PR.

[tarun1sisodia]

Do you think it's ready to merge then? I would like to add CI even if it's after this PR.

Yes ofcourse of you want them merge it or add ci for zig

[viferga]

Do you think it's ready to merge then? I would like to add CI even if it's after this PR.

Yes ofcourse of you want them merge it or add ci for zig

I prefer if you add it.

[viferga]

@tarun1sisodia can you add zig to the ci? I will leave it as draft meanwhile, check out tools/metacall-environment.sh