Publish as versioned Gitea module; move dictionary pipeline out

- Rename module to gitea.iliadenisov.ru/developer/scrabble-solver so it can be
  consumed as a versioned dependency (no go.work replace / CI clone).
- De-internalize wordlist and dictdawg as public packages.
- Remove cmd/builddict, dictprep/, the dictionaries submodule and the dawg
  Makefile: the word-list parsing and DAWG build now live in the separate
  scrabble-dictionary repository, which publishes the DAWG set as a release artifact.
- internal/dict loads the committed dawg/en_sowpods.dawg fixture for cmd/stress.
- Update README/CLAUDE docs accordingly.

cmd/stress/main.go

@@ -12,10 +12,10 @@ import (
 	"strings"
 	"time"
 
-	"scrabble-solver/internal/dict"
-	"scrabble-solver/rules"
-	"scrabble-solver/scrabble"
-	"scrabble-solver/selfplay"
+	"gitea.iliadenisov.ru/developer/scrabble-solver/internal/dict"
+	"gitea.iliadenisov.ru/developer/scrabble-solver/rules"
+	"gitea.iliadenisov.ru/developer/scrabble-solver/scrabble"
+	"gitea.iliadenisov.ru/developer/scrabble-solver/selfplay"
 )
 
 func main() {
@@ -24,7 +24,7 @@ func main() {
 
 	rs := rules.English()
 	if !dict.EnglishAvailable() {
-		log.Fatal("English dictionary not available; run `go run ./cmd/builddict` first")
+		log.Fatal("English dictionary not available: dawg/en_sowpods.dawg missing")
 	}
 	f, err := dict.EnglishDAWG()
 	if err != nil {