fix: optional project ref flag for snippets command

[sweatybridge]

What kind of change does this PR introduce?

feature

What is the new behavior?

Supports supabase snippets list --project-ref <ref> flag.

Also refactors services command for consistent version check.

Additional context

Add any other context or screenshots.

[coveralls]

Pull Request Test Coverage Report for Build 12211395881

Details

• 2 of 40 (5.0%) changed or added relevant lines in 5 files are covered.
• 7 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+0.06%) to 59.647%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
cmd/root.go	0	1	0.0%
internal/start/start.go	1	2	50.0%
internal/snippets/list/list.go	0	2	0.0%
internal/services/services.go	0	34	0.0%

Files with Coverage Reduction	New Missed Lines	%
internal/services/services.go	2	0.0%
internal/gen/keys/keys.go	5	12.9%

Totals
Change from base Build 12198412388:	0.06%
Covered Lines:	6393
Relevant Lines:	10718

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💛 - Coveralls