fix: use import type for GraphConfig, remove verbatim-module-syntax exclusion

The verbatim-module-syntax lint rule was correctly flagging that
GraphConfig is only used in a type position (typeof GraphConfig). Since
typeof resolves purely at the type level, import type works fine here
and is the correct form. No lint exclusion needed.

Also: deno fmt across all files (markdown line wrapping).

src/pg/mod.ts

@@ -1,3 +1,3 @@
 // Postgres host — not yet implemented
 // Will mirror sqlite/ structure with pgTable, jsonb(), timestamp(), pgEnum, etc.
-// Import pattern: import { ... } from "@alkdev/storage/pg"
+// Import pattern: import { ... } from "@alkdev/storage/pg"