feat(migrate): add export clerk and export supabase, and import by export run ID

.changeset/migrate-export.md

@@ -0,0 +1,5 @@
+---
+"clerk": minor
+---
+
+Add `clerk migrate export clerk` and `clerk migrate export supabase`, and let `clerk migrate import` take the export's run ID in place of a file and `--source`. `clerk migrate` is still experimental and needs `CLERK_EXPERIMENTAL=migrate`.

.gitignore

@@ -44,3 +44,7 @@ test/e2e/.har
 
 # Local planning/spec docs
 docs/superpowers/
+
+# Local migration exports and the credentials that produced them
+exports/
+*service-account*.json

packages/cli-core/package.json

@@ -7,7 +7,7 @@
   },
   "type": "module",
   "scripts": {
-    "build": "bun build ./src/cli.ts --outfile ./dist/cli.js --target node --external @napi-rs/keyring --minify",
+    "build": "bun build ./src/cli.ts --outfile ./dist/cli.js --target node --external @napi-rs/keyring --external bun --external bun:sqlite --minify",
     "build:compile": "bun build --compile --minify --no-compile-autoload-dotenv --no-compile-autoload-bunfig ./src/cli.ts --outfile ./dist/clerk",
     "dev": "bun run ./src/cli.ts",
     "typecheck": "tsc --noEmit -p tsconfig.json",