fix(apisec): load embedded schemas on Windows

[Xuxchloris]

Problem

On Windows, APISec cannot load its embedded OpenAPI schema or CLI mapping. filepath.Join produces paths such as v26.05\openapi.json, but embed.FS follows the io/fs contract and accepts slash-separated paths only. This prevents the dynamic APISec command tree from being registered in Windows builds.

Cause

The embedded resource names were constructed with the OS-specific path/filepath package instead of the slash-based path package required by io/fs.

Change

Use path.Join for both embedded schema resource paths. No filesystem paths or runtime API behavior are otherwise changed.

Validation

• go test ./products/apisec (Windows; passes, and failed with the embedded-path error before this change)
• go vet ./...
• go build -o chaitin-cli.exe .
• go test ./... (APISec and all other packages pass; the existing config package still has three unrelated Windows-only failures from POSIX mode and symlink privilege assumptions)