Keep community products out of saved outfits

Saving an outfit (POST /api/outfits.php) sent its community products to IMVU. They're now taken out (any ID in
the community range, known or not), the request re-signed, and the products remembered under the outfit's ID,
then added back when the client loads its saved outfits (marked AP if one is adult).

Co-Authored-By: Claude Opus 5.5 <[email protected]>

internal/products/state.go

@@ -25,8 +25,9 @@ type state struct {
 }
 
 type stateData struct {
-	IDs  map[string]int64      `json:"ids"`  // product ID -> local ID
-	Worn map[string]wornOutfit `json:"worn"` // IMVU user ID -> what they wear
+	IDs     map[string]int64      `json:"ids"`               // product ID -> local ID
+	Worn    map[string]wornOutfit `json:"worn"`              // IMVU user ID -> what they wear
+	Outfits map[string][]string   `json:"outfits,omitempty"` // saved outfit ID -> its community products
 }
 
 // wornOutfit is an account's outfit as last saved or sent: the IMVU products IMVU got, and the community products
@@ -109,6 +110,24 @@ func (s *state) setWorn(user string, imvu []int64, products []string) error {
 	return s.saveLocked()
 }
 
+// outfit is the community products saved with an outfit (by IMVU's outfit ID).
+func (s *state) outfit(id string) []string {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return append([]string(nil), s.data.Outfits[id]...)
+}
+
+// setOutfit remembers the community products saved with an outfit.
+func (s *state) setOutfit(id string, products []string) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if s.data.Outfits == nil {
+		s.data.Outfits = map[string][]string{}
+	}
+	s.data.Outfits[id] = append([]string(nil), products...)
+	return s.saveLocked()
+}
+
 // sameSet reports whether a and b hold the same IDs, in any order.
 func sameSet(a, b []int64) bool {
 	if len(a) != len(b) {