chore(db): migration for previous commits (#10319)

Recreate the blocks and block lists tables.

---------

Co-authored-by: bt90 <btom1990@googlemail.com>

internal/db/sqlite/sql/migrations/folder/04-alter-blocks-tables.sql

@@ -0,0 +1,51 @@
+-- Copyright (C) 2025 The Syncthing Authors.
+--
+-- This Source Code Form is subject to the terms of the Mozilla Public
+-- License, v. 2.0. If a copy of the MPL was not distributed with this file,
+-- You can obtain one at https://mozilla.org/MPL/2.0/.
+
+-- Copy blocks to new table with fewer indexes
+
+DROP TABLE IF EXISTS blocks_v4
+;
+
+CREATE TABLE blocks_v4 (
+    hash BLOB NOT NULL,
+    blocklist_hash BLOB NOT NULL,
+    idx INTEGER NOT NULL,
+    offset INTEGER NOT NULL,
+    size INTEGER NOT NULL,
+    PRIMARY KEY (hash, blocklist_hash, idx)
+) STRICT, WITHOUT ROWID
+;
+
+INSERT INTO blocks_v4 (hash, blocklist_hash, idx, offset, size)
+SELECT hash, blocklist_hash, idx, offset, size FROM blocks ORDER BY hash, blocklist_hash, idx
+;
+
+DROP TABLE blocks
+;
+
+ALTER TABLE blocks_v4 RENAME TO blocks
+;
+
+-- Copy blocklists to new table with fewer indexes
+
+DROP TABLE IF EXISTS blocklists_v4
+;
+
+CREATE TABLE blocklists_v4 (
+    blocklist_hash BLOB NOT NULL PRIMARY KEY,
+    blprotobuf BLOB NOT NULL
+) STRICT, WITHOUT ROWID
+;
+
+INSERT INTO blocklists_v4 (blocklist_hash, blprotobuf)
+SELECT blocklist_hash, blprotobuf FROM blocklists ORDER BY blocklist_hash
+;
+
+DROP TABLE blocklists
+;
+
+ALTER TABLE blocklists_v4 RENAME TO blocklists
+;