Drop the single-database split and re-baseline the control migrations

Every deployment has been through the per-blog split, so the code that
performed it (split.go, control migrations 00002–00007) is dead weight, and a
fresh install replaying six migrations only to drop the tables again was
silly. The control chain is now a single 00001_init.sql with the final users
and blogs shape, matching the blog chain.

Goose ignores versions recorded in the database that no longer exist in the
source, but refuses a future migration numbered below the database's highest
version. Databases that went through the split therefore need
`DELETE FROM goose_db_version WHERE version_id > 1` once; README and
AGENTS.md say so.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Sd8UPWrvyYCLj97JexNw3A

1 files changed, 0 insertions, 13 deletions

diff --git a/internal/db/migrations/control/00004_section_placement.sql b/internal/db/migrations/control/00004_section_placement.sql
deleted file mode 100644
index c36787e..0000000
--- a/internal/db/migrations/control/00004_section_placement.sql
+++ /dev/null
@@ -1,13 +0,0 @@
--- +goose Up
--- Announcements are placed in a column (left, main, right) at its top or bottom.
-ALTER TABLE sections DROP CONSTRAINT sections_placement_check;
-UPDATE sections SET placement = CASE placement WHEN 'above' THEN 'main-top' WHEN 'below' THEN 'main-bottom' ELSE 'left-top' END;
-ALTER TABLE sections ALTER COLUMN placement SET DEFAULT 'main-top';
-ALTER TABLE sections ADD CONSTRAINT sections_placement_check
-    CHECK (placement IN ('left-top', 'left-bottom', 'main-top', 'main-bottom', 'right-top', 'right-bottom'));
-
--- +goose Down
-ALTER TABLE sections DROP CONSTRAINT sections_placement_check;
-UPDATE sections SET placement = CASE placement WHEN 'main-top' THEN 'above' WHEN 'main-bottom' THEN 'below' ELSE 'sidebar' END;
-ALTER TABLE sections ALTER COLUMN placement SET DEFAULT 'above';
-ALTER TABLE sections ADD CONSTRAINT sections_placement_check CHECK (placement IN ('above', 'below', 'sidebar'));