chore(protocol): improve IPv6 address. (#268)

* docs: improve documentation and configuration handling

- Clarify valid values for the IP protocol in usage messages for both main application and proxy settings

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

* test: improve IPv6 command execution tests

- Add a new test function `TestCommandWithIPv6` to check command execution with an IPv6 address
- Initialize test variables and expected output for the IPv6 command test
- Set up a `Plugin` struct with IPv6 host, user, port, key path, script, and command timeout for testing
- Verify that `plugin.Exec()` returns `nil` (no error) in the IPv6 test
- Assert that the output of the command execution matches the expected output in the IPv6 test

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

* test: enhance test suite and CI robustness

- Add support for IPv6 protocol in `TestCommandWithIPv6` test case in `plugin_test.go`

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

* update

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

* update

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

* update

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

* update

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

* update2

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

* update3

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

* update4

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

* update5

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

* update5

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

* update5

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

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Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

Makefile

@@ -117,6 +117,8 @@ ssh-server:
 	rm -rf /etc/ssh/ssh_host_rsa_key /etc/ssh/ssh_host_dsa_key
 	sed -i 's/^#PubkeyAuthentication yes/PubkeyAuthentication yes/g' /etc/ssh/sshd_config
 	sed -i 's/AllowTcpForwarding no/AllowTcpForwarding yes/g' /etc/ssh/sshd_config
+	sed -i 's/^#ListenAddress 0.0.0.0/ListenAddress 0.0.0.0/g' /etc/ssh/sshd_config
+	sed -i 's/^#ListenAddress ::/ListenAddress ::/g' /etc/ssh/sshd_config
 	./tests/entrypoint.sh /usr/sbin/sshd -D &
 
 coverage: