feat: show estimated tool token context in hermes tools checklist (#3805)

* feat: show estimated tool token context in hermes tools checklist

Adds a live token estimate indicator to the bottom of the interactive
tool configuration checklist (hermes tools / hermes setup). As users
toggle toolsets on/off, the total estimated context cost updates in
real time.

Implementation:
- tools/registry.py: Add get_schema() for check_fn-free schema access
- hermes_cli/curses_ui.py: Add optional status_fn callback to
  curses_checklist — renders at bottom-right of terminal, stays fixed
  while items scroll
- hermes_cli/tools_config.py: Add _estimate_tool_tokens() using
  tiktoken (cl100k_base, already installed) to count tokens in the
  JSON-serialised OpenAI-format tool schemas. Results are cached
  per-process. The status function deduplicates overlapping tools
  (e.g. browser includes web_search) for accurate totals.
- 12 new tests covering estimation, caching, graceful degradation
  when tiktoken is unavailable, status_fn wiring, deduplication,
  and the numbered fallback display

* fix: use effective toolsets (includes plugins) for token estimation index mapping

The status_fn closure built ts_keys from CONFIGURABLE_TOOLSETS but the
checklist uses _get_effective_configurable_toolsets() which appends plugin
toolsets. With plugins present, the indices would mismatch, causing
IndexError when selecting a plugin toolset.

tools/registry.py

@@ -149,6 +149,15 @@ class ToolRegistry:
         """Return sorted list of all registered tool names."""
         return sorted(self._tools.keys())
 
+    def get_schema(self, name: str) -> Optional[dict]:
+        """Return a tool's raw schema dict, bypassing check_fn filtering.
+
+        Useful for token estimation and introspection where availability
+        doesn't matter — only the schema content does.
+        """
+        entry = self._tools.get(name)
+        return entry.schema if entry else None
+
     def get_toolset_for_tool(self, name: str) -> Optional[str]:
         """Return the toolset a tool belongs to, or None."""
         entry = self._tools.get(name)