Remove conflicting migrations, keep schema in 000001

000001 was modified to include public_id, version, delete_timestamp
but 000002/000003 tried to ALTER TABLE to add the same columns,
causing duplicate column errors on existing databases where
migrations had run partially.

Fix: only 000001 with the full schema. No 000002/000003.

migrations/000002_add_versioning.sql

@@ -1,10 +0,0 @@
--- +goose Up
-ALTER TABLE flashcard ADD COLUMN public_id INTEGER NOT NULL DEFAULT 0;
-ALTER TABLE flashcard ADD COLUMN version INTEGER NOT NULL DEFAULT 1;
-UPDATE flashcard SET public_id = _id WHERE public_id = 0;
-CREATE UNIQUE INDEX IF NOT EXISTS idx_flashcard_public_id_version ON flashcard(public_id, version);
-
--- +goose Down
-DROP INDEX IF EXISTS idx_flashcard_public_id_version;
-ALTER TABLE flashcard DROP COLUMN version;
-ALTER TABLE flashcard DROP COLUMN public_id;

migrations/000003_add_delete_timestamp.sql

@@ -1,5 +0,0 @@
--- +goose Up
-ALTER TABLE flashcard ADD COLUMN delete_timestamp TEXT;
-
--- +goose Down
-ALTER TABLE flashcard DROP COLUMN delete_timestamp;