feat: add organization vault support (#3)

* feat: add organization vault support

- Add RSA-OAEP decryption (type 3: SHA-256, type 4: SHA-1)
- Decrypt user's RSA private key from sync response (PKCS8 DER)
- Decrypt organization keys using user's RSA private key
- Route cipher decryption to correct key based on organizationId
- Personal vault items continue to work unchanged

Adds 11 new unit tests covering:
- RSA cipher string parsing (type 3/4)
- RSA-OAEP round-trip (SHA-1 and SHA-256)
- Private key decrypt/parse round-trip
- Org key decrypt + encKey/macKey split
- Cipher decryption with org vs personal key
- Backward compatibility for personal items

Also adds CI/CD pipeline (.github/workflows/ci.yml):
- Tests + build on PRs and main pushes
- Docker build + push to GHCR on main

* fix: split concatenated .gitignore entries

* chore: clean up gitignore

.github/workflows/ci.yml

@@ -0,0 +1,45 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+
+      - name: Run tests
+        run: go test ./... -v -count=1
+
+      - name: Build
+        run: go build ./...
+
+  docker:
+    needs: test
+    if: github.event_name == 'push' && github.ref == 'refs/heads/main'
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - uses: docker/build-push-action@v6
+        with:
+          context: .
+          push: true
+          tags: ghcr.io/turbootzz/vaultwarden-api:latest