UR-Nexus 1.68.10

• ToolSearchTool no longer registers on runtimes where it cannot work. Its
  purpose is fetching schemas for tools whose definitions were deferred, and
  deferral needs the runtime to expand tool_reference blocks — an
  Anthropic-native beta shape that no UR runtime supports (UR runs on Ollama,
  OpenAI-compatible servers and vendor CLIs). isEnabled() consulted only
  isToolSearchEnabledOptimistic(), which reads the mode, and the mode
  defaults to 'tst' (on). The tool therefore registered on every run: its
  description shipped with each request, and the model was offered a tool that
  could not function, because nothing was ever deferred for it to fetch.
• Audit note on the surface as a whole: 168 commands, of which 8 touch a
  feature flag that is not compiled in, and in each case the flag gates a
  sub-feature rather than the command. 89 of 91 flags are absent from shipped
  builds. Two of those (CONTEXT_COLLAPSE, REACTIVE_COMPACT) would have
  failed on the first turn if enabled and were fixed in 1.68.2.