BB1: full E40 S16F11 body — MF, PRRECIPEMETHOD, RCPVARS, PRPROCESSPARAMS

Replaces the simplified <L,3 PRJOBID PPID MTRLOUTSPEC> demo body with
the full SEMI E40-0705 §10.2 shape:

  <L,5 PRJOBID MF PRRECIPEMETHOD
       <L,2 PPID <L,n <L,2 RCPPARNM RCPPARVAL>>>
       <L,n MTRLOUTSPEC>
       <L,n <L,2 PARAMNAME PARAMVAL>>>

ProcessJob now carries the extra fields (MaterialFlag, ProcessRecipeMethod,
RcpVar[], ProcessParam[]) so a tool's recipe engine can later consume
the recipe-variable overrides and per-job process parameters.  Server
S16F11 dispatch populates them via the new ProcessJobStore::set_e40_extras
helper after a successful create.

MaterialFlag + ProcessRecipeMethod enums live in their own tiny header
(`e40_constants.hpp`) so process_jobs.hpp (the store) can use them
without dragging in messages_helpers.hpp (which would create a circular
include via data_model.hpp).

The simplified 3-arg HostHandler::send_create_process_job convenience
remains; it constructs a sensible-default PRJobCreateRequest internally.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

include/secsgem/gem/e40_constants.hpp

@@ -0,0 +1,28 @@
+#pragma once
+
+#include <cstdint>
+
+// E40-0705 §10.2 constants used by both the runtime stores (e.g.
+// ProcessJob carries MaterialFlag) and the generated message catalog
+// (S16F11 PRJobCreate body shape).  Kept in its own tiny header so the
+// store side can use them without pulling in messages_helpers.hpp,
+// which in turn pulls in data_model.hpp -> the stores themselves.
+
+namespace secsgem::gem {
+
+// E40 S16F11 MF (Material Flag).  Classifies what the material outspec
+// represents.  Values from SEMI E40 §10.2.
+enum class MaterialFlag : uint8_t {
+  Substrate = 0,  // outspec holds substrate / wafer IDs
+  Carrier   = 1,  // outspec holds carrier IDs
+  Other     = 2,  // tool-defined
+};
+
+// E40 S16F11 PRRECIPEMETHOD.  Tells equipment what to do with the
+// recipe id in RCPSPEC.
+enum class ProcessRecipeMethod : uint8_t {
+  RecipeOnly               = 0,  // PPID identifies an existing recipe; use as is
+  RecipeWithVariableTuning = 1,  // PPID + apply RCPVARLIST overrides
+};
+
+}  // namespace secsgem::gem