workflow: rename dsh-workflow-vm to dsh-workflow-workerthread

Pure mechanical rename now that the package's internals are the
worker-thread engine: directory, package name, spec/e2e filenames,
module tags and logger prefixes, tsconfig/knip/run-gates/AGENTS.md
references, example cordis.yml plugin ids, doc links; catalogs
regenerated and the lockfile refreshed.

examples/acp-agent/tests/acp.snapshot.ts

@@ -108,7 +108,7 @@ const SCENARIOS: Scenario[] = [
   { name: 'subagent-fork', hasModelTurn: true, recorded: true, childSessions: 1 },
   { name: 'subagent-mixed', hasModelTurn: true, recorded: true, childSessions: 2 },
   // The workflow tool: the model writes a one-child orchestration script; the
-  // child runs as a spawn subagent inside the vm engine (its session is the
+  // child runs as a spawn subagent under the worker-thread engine (its session is the
   // child fixture), and the tool result carries the script's return value.
   { name: 'workflow-run', hasModelTurn: true, recorded: true, childSessions: 1 },
   // Hook matrix — one scenario per hook point × its headline Decision outcome,