Worker pool fails to start when clice is executed via PATH: "no such file or directory"

[tsurumi-yizhou]

Describe the bug
When running clice from a directory that is in the system PATH (e.g., ~/.clice/clice added to PATH), the server fails to start w
ith the error:

failed to start worker pool: no such file or directory

The root cause is that resolve_self_path() in src/clice.cc uses std::filesystem::absolute(argv[0]) to determine the executable p
ath. When argv[0] is just "clice" (no path separators), absolute() resolves it relative to the current working directory, not th
e actual location of the executable in PATH. This causes spawn_worker() to fail when trying to launch worker processes.

To Reproduce

1. Build clice and copy the binary to ~/.clice/
2. Add ~/.clice to PATH: export PATH="$HOME/.clice:$PATH"
3. Run clice from any directory other than ~/.clice/:
   cd /tmp
   clice --mode=pipe
4. See error: failed to start worker pool: no such file or directory

Expected behavior
clice should correctly resolve its executable path regardless of how it is invoked (absolute path, relative path, or via PATH).
When argv[0] contains no path separators, it should search the PATH environment variable to find the actual executable location.

Desktop:

• OS: macOS 15
• Version latest main branch