Seed from go-template-repo, renamed to simplexcalc

The template's files at a77fd30, without its history or LICENSE, after
script/rename simplexcalc.

Model: opus-5-5

internal/database/schema/000.sql

@@ -0,0 +1,15 @@
+-- 000.sql: the bootstrap migration. It creates only the ledger that
+-- records which migrations have run; every other migration is recorded
+-- in it. Applied when the schema_migrations table is missing, and never
+-- again.
+--
+-- Never edit an applied migration. Add a new numbered file instead: the
+-- ledger records versions, not contents, so an edited file is applied
+-- nowhere and diverges everywhere.
+
+CREATE TABLE IF NOT EXISTS schema_migrations (
+    version     INTEGER PRIMARY KEY,
+    applied_at  TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ', 'now'))
+);
+
+INSERT OR IGNORE INTO schema_migrations (version) VALUES (0);