fix: quote Antigravity config paths in uninstaller

[aikinley]

Summary

• pass the Antigravity config path to the Python fallback through sys.argv instead of interpolating it into generated source
• keep removal scoped to mcpServers.monk while preserving unrelated configuration
• update both shipped POSIX uninstaller mirrors
• add a network-free regression for apostrophes in the config path

Why

An apostrophe in $HOME terminates the generated Python string in v0.1.54. The fallback error is intentionally swallowed, so uninstall reports success but leaves the dead Monk MCP registration behind.

Validation

• pristine v0.1.54 regression: exits 1 because mcpServers.monk remains
• fixed regression: tests/uninstall-monk-agent-antigravity-python-path.sh passes
• C:\Program Files\Git\bin\bash.exe -n scripts/uninstall-monk-agent.sh
• SHA-256 equality verified across both shipped uninstaller mirrors
• git diff --check

Generated artifacts

GENERATED.md says the public tree is generated from the private monk-agent/plugin source. This PR updates the mirrored public artifacts consistently; the corresponding source change should be ported before the next regeneration.

Fixes #254