D1's exec() treats newlines as statement separators, causing multiline
CREATE TABLE statements to be truncated after the first line and return
"incomplete input: SQLITE_ERROR" on every request.
Fix: switch run_migrations() in D1Repository to use prepare(sql).run()
instead of exec(sql), which treats the full string as a single statement.
Also moves db and handlers modules from src/bin/api/ to src/ (library
modules), adds justfile with build/deploy/migrate recipes, adds
migrations/schema.sql for direct wrangler d1 execute usage, and adds
wrangler.toml for worker deployment configuration.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Elijah Voigt