soul: parameterize CGI ID + add dharma_room_turn handler

- soul.el: SOUL_CGI_ID, SOUL_ENGRAM_PATH, SOUL_IDENTITY env vars;
  state_set("soul_snapshot_path") so callers can find it; only call
  init_soul_edges() when cgi_id == "ntn-genesis"
- chat.el: handle_dharma_room_turn — soul builds its own context from its
  own engram, assembles system prompt, calls LLM, persists episodic memory;
  also fix is_new_tool scoping bug in handle_chat_agentic (use has_tool)
- routes.el: wire dharma_room_turn event type before chat_as_soul branch
- rebuild dist/neuron: handle_dharma_room_turn now compiled in

routes.elh

@@ -1,4 +1,4 @@
-// auto-generated by elc --emit-header - do not edit
+// auto-generated by elc --emit-header — do not edit
 extern fn strip_query(path: String) -> String
 extern fn err_404(path: String) -> String
 extern fn err_405(method: String, path: String) -> String