fix: sync version and use context manager for file handle

[hell0gunawan]

Summary

Two independent fixes in one PR:

1. Version sync (#62)

• __init__.py: 0.0.17 → 0.0.18
• Matches pyproject.toml version (already 0.0.18)

2. File handle leak fix (#63)

• play_audio(): changed open() to use with context manager
• Prevents file handle left open after reading

Both are small, isolated, low-risk fixes with no chance of breaking existing functionality.

Changes

- __version__ = "0.0.17"
+ __version__ = "0.0.18"

- play(open(file_path, "rb").read())
+ with open(file_path, "rb") as f:
+     play(f.read())

Addresses

• Closes fix: version mismatch between __init__.py (0.0.17) and pyproject.toml (0.0.18) #62
• Closes fix(server): play_audio leaks file handle — open() without context manager #63