Mount target parameter does not get ~ inetpreted as home on target VM anymore

[amorskoy]

Describe the bug
Please see full context at canonical/operator#2746 (comment)
Issue: "~" in mount target is taken literally in 1.17 while expended to home in 1.16.

root@andrey /h/andrey# multipass mount --type native ~andrey/onboarding-httpbin-task/ test:~/onboarding-httpbin-task
root@andrey /h/andrey# multipass info test | grep -A1 Mounts
Mounts:         /home/andrey/onboarding-httpbin-task => /home/ubuntu/~/onboarding-httpbin-task
                    UID map: 0:default

To Reproduce
How, and what happened?

1. multipass mount --type native ~andrey/onboarding-httpbin-task/ test:~/onboarding-httpbin-task
2. Target mount path on VM is /home/ubuntu/~/onboarding-httpbin-task (notice on "~")

Expected behavior
Path should interpret '~' as home directory on guest VM

Logs
Verbosity logs:

root@andrey /h/andrey# mp -vvvv mount --type native ~andrey/onboarding-httpbin-task/ test:~/onboarding-httpbin-task > /tmp/mp.mount.log
[2026-09-21T09:44:40.211] [debug] [mount cmd] mount.cpp:237, `mp::ParseCode multipass::cmd::Mount::parse_args(mp::ArgParser *)`: adding default uid mapping
[2026-09-21T09:44:40.211] [debug] [mount cmd] mount.cpp:276, `mp::ParseCode multipass::cmd::Mount::parse_args(mp::ArgParser *)`: adding default gid mapping
[2026-09-21T09:44:40.215] [info] [qemu-mount-handler] initializing native mount /home/andrey/onboarding-httpbin-task => /home/ubuntu/~/onboarding-httpbin-task in 'test'
[2026-09-21T09:44:40.223] [debug] [FileOps] Saved file `/var/snap/multipass/common/data/multipassd/multipassd-vm-instances.json` successfully in attempt #1

Additional info

• OS: Ubuntu 26.04
• CPU architecture or model: amd64
• multipass version = 1.17.0-dev.4182+ga584e5fa
• multipass info = see above
• multipass get local.driver = qemu

Additional context
Suggested root cause - canonical/operator#2746 (comment)