vm(hako): add v1 reader/dispatcher (flagged), commonize mir_call handler, share block scan; smokes: add v1 hakovm canary; docs: 20.37/20.38 plans, OOB policy; runner: v1 hakovm toggle; include SKIP summary

src/backend/mir_interpreter/handlers/mod.rs

@@ -23,6 +23,7 @@ mod boxes_void_guards;
 mod call_resolution;
 mod calls;
 mod externals;
+mod extern_provider;
 mod memory;
 mod misc;