e42: enhanced (formatted) process programs S7F23-F26

E42 was an explicit out-of-scope item in the prior COMPLIANCE.md.
This commit closes it.

Wire messages added via the catalog:
  S7F23  Formatted PP Send       (H↔E, W=1)
  S7F24  Formatted PP Ack        (ProcessProgramAck)
  S7F25  Formatted PP Request    (PPID, W=1)
  S7F26  Formatted PP Data       (E→H, no reply)

Body shape: <L,4 PPID MDLN SOFTREV <L,n <L,2 CCODE <L,m <L,2
PNAME PVAL>>>>>.  PVAL is declared ITEM so any SECS-II Item type
round-trips — proven by a test that mixes ASCII, BOOLEAN, U4, F8,
Binary, and nested List values in one step.

RecipeStore extension:
  add_formatted(ppid, FormattedRecipe{mdln, softrev, steps})
  get_formatted(ppid) -> optional<FormattedRecipe>
  has_formatted(ppid) -> bool

Formatted + opaque views live alongside each other: a PPID can carry
both, size() counts unique PPIDs.  remove() kills both views.

Six new tests cover wire round-trip per function, every
ProcessProgramAck code, ITEM passthrough, and the store's dual-view
semantics.

COMPLIANCE.md updated: E30 §6.17 row mentions S7F23-F26, S5 message
table grows two rows, §8 "out of scope" entry for E42 removed.

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

include/secsgem/gem/store/recipes.hpp

@@ -7,6 +7,8 @@
 #include <utility>
 #include <vector>
 
+#include "secsgem/secs2/item.hpp"
+
 namespace secsgem::gem {
 
 enum class ProcessProgramAck : uint8_t {
@@ -19,6 +21,28 @@ enum class ProcessProgramAck : uint8_t {
   PerformanceError = 6,
 };
 
+// One parameter on a formatted-PP step (E42).  Name + arbitrary
+// SECS-II Item value.
+struct FormattedRecipeParam {
+  std::string name;
+  secs2::Item value;
+};
+
+// One step of a formatted PP: a CCODE (command name) and its
+// parameter list.  Matches the wire shape of S7F23/F26 row entries.
+struct FormattedRecipeStep {
+  std::string ccode;
+  std::vector<FormattedRecipeParam> params;
+};
+
+// Equipment / model metadata that travels with a formatted PP.  Set
+// on add_formatted; round-tripped through S7F23/F26.
+struct FormattedRecipe {
+  std::string mdln;        // model name
+  std::string softrev;     // software revision
+  std::vector<FormattedRecipeStep> steps;
+};
+
 class RecipeStore {
  public:
   void add(std::string ppid, std::string body) {
@@ -31,19 +55,47 @@ class RecipeStore {
   }
   std::vector<std::string> list() const {
     std::vector<std::string> out;
-    out.reserve(by_ppid_.size());
+    out.reserve(by_ppid_.size() + formatted_.size());
     for (const auto& [k, _] : by_ppid_) out.push_back(k);
+    for (const auto& [k, _] : formatted_) {
+      if (!by_ppid_.count(k)) out.push_back(k);
+    }
     return out;
   }
   ProcessProgramAck remove(const std::string& ppid) {
-    if (!by_ppid_.count(ppid)) return ProcessProgramAck::PpidNotFound;
-    by_ppid_.erase(ppid);
-    return ProcessProgramAck::Accept;
+    bool found = (by_ppid_.erase(ppid) > 0) | (formatted_.erase(ppid) > 0);
+    return found ? ProcessProgramAck::Accept : ProcessProgramAck::PpidNotFound;
+  }
+  // Unique PPID count.  A PPID with both opaque and formatted views
+  // counts once.
+  std::size_t size() const {
+    std::size_t n = by_ppid_.size();
+    for (const auto& [k, _] : formatted_) {
+      if (!by_ppid_.count(k)) ++n;
+    }
+    return n;
+  }
+
+  // ---- E42 formatted PPs ------------------------------------------------
+  // A formatted recipe lives alongside any opaque-body PP with the same
+  // PPID.  Most tools pick one form or the other; storing both
+  // independently lets a host poke at the formatted view while a legacy
+  // app reads the opaque view.
+  void add_formatted(std::string ppid, FormattedRecipe r) {
+    formatted_.insert_or_assign(std::move(ppid), std::move(r));
+  }
+  std::optional<FormattedRecipe> get_formatted(const std::string& ppid) const {
+    auto it = formatted_.find(ppid);
+    if (it == formatted_.end()) return std::nullopt;
+    return it->second;
+  }
+  bool has_formatted(const std::string& ppid) const {
+    return formatted_.count(ppid) > 0;
   }
-  std::size_t size() const { return by_ppid_.size(); }
 
  private:
-  std::map<std::string, std::string> by_ppid_;
+  std::map<std::string, std::string>     by_ppid_;
+  std::map<std::string, FormattedRecipe> formatted_;
 };
 
 }  // namespace secsgem::gem