feat: alias migration down command as reset

[sweatybridge]

What kind of change does this PR introduce?

relates to #611

What is the new behavior?

Adds an alias for db reset so that it's easier to revert the last n migrations without inputting the full version string.

$ supabase db start
Seeding globals from roles.sql...
Applying migration 20250510162534_table.sql...
Applying migration 20250510162754_index.sql...
NOTICE (42P06): schema "supabase_migrations" already exists, skipping
Seeding data from supabase/seed.sql...
A new version of Supabase CLI is available: v2.23.4 (currently installed v)
We recommend updating regularly for new features and bug fixes: https://supabase.com/docs/guides/cli/getting-started#updating-the-supabase-cli
$ supabase migrations down
Connecting to local database...
Resetting local database to version: 20250510162534
Recreating database...

Additional context

https://x.com/nicolaygerold/status/1928396644241879115

[avallete]

LGTM

MIght wanna inform the user that this is a destructive operation for his data just in case ? 🤔

[coveralls]

Pull Request Test Coverage Report for Build 15439830073

Details

• 15 of 42 (35.71%) changed or added relevant lines in 4 files are covered.
• 5 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-0.06%) to 54.84%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
cmd/db.go	0	3	0.0%
internal/migration/down/down.go	13	17	76.47%
cmd/migration.go	0	10	0.0%
internal/db/reset/reset.go	2	12	16.67%

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

Totals
Change from base Build 15438467837:	-0.06%
Covered Lines:	5977
Relevant Lines:	10899

---

💛 - Coveralls

[sweatybridge]

Yup, we print a confirmation when running migration down.