remove redundant isVerbNonIndependent and consolidate test lanes

- drop always-true isVerbNonIndependent export; collapse shouldMerge branch
- remove node-compat exclusion list from bun-src-full lane
- simplify test:fast (drop test:runtime:compat), test:env, test:smoke:dist scripts
- rename test:launcher:env:src -> test:env in docs

src/token-merger.test.ts

@@ -0,0 +1,7 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import * as tokenMerger from './token-merger';
+
+test('does not expose the redundant verb non-independent predicate', () => {
+  assert.equal('isVerbNonIndependent' in tokenMerger, false);
+});