CI: build-only validation (no make/python/contexts); commit folded erudit.txt

- build.yaml dropped the release step whose ${{ github.* }} contexts failed the Gitea
  workflow compile (the run produced 0 jobs); it now inlines go run (no make dependency)
  and reads the committed dictprep/russian/erudit.txt (no python dependency).
- erudit.txt is scrabble.txt with Ё→Е folded (dictprep/fold_yo.py); it reproduces the
  canonical ru_erudit.dawg byte-for-byte. Release artifacts are published manually for now
  (see README).

.gitea/workflows/build.yaml

@@ -1,14 +1,15 @@
 name: build
 
-# Builds the dictionary DAWGs on every push/PR (validation) and, on a vX.Y.Z tag,
-# packages them flat into scrabble-dawg-<tag>.tar.gz and attaches it to the Gitea release.
-# The build pins the published scrabble-solver builders (GOPRIVATE -> direct VCS fetch from
-# this Gitea), so the on-disk format matches the running backend exactly.
+# Validation gate: rebuilds the three dictionary DAWGs on every push/PR and checks they are
+# non-empty. The build pins the published scrabble-solver builders (GOPRIVATE -> direct VCS
+# fetch from this Gitea), so the on-disk format and letter indexing match the running backend
+# exactly. Release artifacts (scrabble-dawg-<tag>.tar.gz attached to the Gitea release) are
+# published from this output; see README.md. Inlined go run (no make/python dependency on the
+# runner).
 
 on:
   push:
     branches: [master]
-    tags: ['v*']
   pull_request:
     branches: [master]
 
@@ -32,31 +33,11 @@ jobs:
 
       - name: Build DAWGs
         run: |
-          make dawg
+          mkdir -p dawg
+          go run ./cmd/builddict -dict dictionaries/english/sowpods.txt -alphabet latin   -name en_sowpods  -out dawg
+          go run ./cmd/builddict -dict dictprep/russian/scrabble.txt    -alphabet russian -name ru_scrabble -out dawg
+          go run ./cmd/builddict -dict dictprep/russian/erudit.txt      -alphabet russian -name ru_erudit   -out dawg
           ls -la dawg/
           for f in en_sowpods ru_scrabble ru_erudit; do
             test -s "dawg/$f.dawg" || { echo "missing dawg/$f.dawg"; exit 1; }
           done
-
-      - name: Package and publish release artifact
-        if: startsWith(github.ref, 'refs/tags/v')
-        env:
-          TOKEN: ${{ github.token }}
-          API: ${{ github.server_url }}/api/v1/repos/${{ github.repository }}
-        run: |
-          set -eo pipefail
-          tag="${GITHUB_REF_NAME}"
-          art="scrabble-dawg-${tag}.tar.gz"
-          tar czf "$art" -C dawg en_sowpods.dawg ru_scrabble.dawg ru_erudit.dawg
-          # Create the release (or fetch it if it already exists), then upload the asset.
-          code=$(curl -sS -o /tmp/rel.json -w '%{http_code}' -X POST "$API/releases" \
-            -H "Authorization: token $TOKEN" -H 'Content-Type: application/json' \
-            -d "{\"tag_name\":\"$tag\",\"name\":\"$tag\",\"body\":\"Dictionary DAWG set $tag (en_sowpods, ru_scrabble, ru_erudit).\"}")
-          if [ "$code" != "201" ]; then
-            echo "release POST returned $code; fetching existing release for tag $tag"
-            curl -sS -o /tmp/rel.json "$API/releases/tags/$tag" -H "Authorization: token $TOKEN"
-          fi
-          rel_id=$(python3 -c 'import json;print(json.load(open("/tmp/rel.json"))["id"])')
-          curl -sS -X POST "$API/releases/$rel_id/assets?name=$art" \
-            -H "Authorization: token $TOKEN" -F "attachment=@$art" -o /tmp/asset.json
-          echo "published $art to release $rel_id"