fix: correct --cwd position in test-opencode-unit recipe

`bun turbo test --cwd packages/opencode` fails because bun resolves
`turbo` from the root workspace before changing directory. Place
`--cwd` immediately after `bun` to match the working pattern used
by lint-opencode. Also drop the OPENCODE_CONFIG_CONTENT env prefix
since auth disabling now lives in test/preload.ts.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: pRizz

justfile

@@ -154,7 +154,7 @@ test-opencode-ui: opencode-install-if-needed
 
 # Run opencode upstream unit tests (turbo: opencode + fork-tests + app)
 test-opencode-unit: opencode-install-if-needed
-    OPENCODE_CONFIG_CONTENT='{"auth":{"enabled":false}}' bun turbo test --cwd packages/opencode
+    bun --cwd packages/opencode turbo test
 
 # Optional submodule drift and dirty state check
 check-opencode-submodule-drift: