Use a neutral compact switch codec and clarify provider size limits

src/data/layerStateTokenLedger.test.mjs

@@ -98,16 +98,11 @@ function withPublishedBase(
 }
 
 function writeCodecFixture(cwd, rows, entries) {
-  const providerCodec = path.join(
-    cwd,
-    'src/layers/streetLevel/providerSwitches.js',
-  );
+  const providerCodec = path.join(cwd, 'src/data/idSwitches.js');
   mkdirSync(path.dirname(providerCodec), { recursive: true });
   writeFileSync(
     providerCodec,
-    readFileSync(
-      new URL('../layers/streetLevel/providerSwitches.js', import.meta.url),
-    ),
+    readFileSync(new URL('./idSwitches.js', import.meta.url)),
   );
   const source = readFileSync(CODEC_SOURCE_PATH, 'utf8');
   const registryEnd = ']);\n\nexport const REGISTERED_LAYER_IDS';