core: make account login upgrades safe while adding multi-account workspace auth (#15487)

Co-authored-by: Kit Langton <kit.langton@gmail.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

AGENTS.md

@@ -122,3 +122,7 @@ const table = sqliteTable("session", {
 - Avoid mocks as much as possible
 - Test actual implementation, do not duplicate logic into tests
 - Tests cannot run from repo root (guard: `do-not-run-tests-from-root`); run from package dirs like `packages/opencode`.
+
+## Type Checking
+
+- Always run `bun typecheck` from package directories (e.g., `packages/opencode`), never `tsc` directly.