Add poll test coverage and improve CI pipeline

18 new tests covering poll lifecycle: creation validation, voting
(duplicate nullifier, missing fields, closed/expired polls), and
sealed-results enforcement (tallies hidden while active, visible
when closed).

CI now runs go vet and tests with -race detector.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: stackdump

.github/workflows/ci.yml

@@ -7,6 +7,18 @@ on:
     branches: [main]
 
 jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version: '1.24'
+
+      - name: Go vet
+        run: go vet ./...
+
   build:
     runs-on: ubuntu-latest
     steps:
@@ -28,8 +40,8 @@ jobs:
         with:
           go-version: '1.24'
 
-      - name: Go tests
-        run: make test
+      - name: Go tests (race detector)
+        run: go test -race -count=1 ./...
 
   js-parity:
     runs-on: ubuntu-latest