refactor: flatten project structure, remove backend/ directory

Move all Go code from backend/ to repo root since there is no separate
frontend. Update module path from github.com/ukeeper/ukeeper-readability/backend
to github.com/ukeeper/ukeeper-readability. Remove redundant test execution
from Dockerfile (CI build job handles testing). Add CLAUDE.md.

Author: umputun

.github/workflows/ci.yml

@@ -22,7 +22,6 @@ jobs:
       - name: set up go
         uses: actions/setup-go@v6
         with:
-          cache-dependency-path: backend
           go-version: "1.25"
         id: go
 
@@ -32,7 +31,6 @@ jobs:
           mongoDBVersion: "5.0"
 
       - name: build and test
-        working-directory: backend
         run: |
           go test -timeout=60s -race -covermode=atomic -coverprofile=$GITHUB_WORKSPACE/profile.cov ./...
           go build -race
@@ -44,13 +42,11 @@ jobs:
         uses: golangci/golangci-lint-action@v9
         with:
           version: "latest"
-          working-directory: backend
 
       - name: submit coverage
         run: |
           go install github.com/mattn/goveralls@latest
           goveralls -service="github" -coverprofile=$GITHUB_WORKSPACE/profile.cov
-        working-directory: backend
         env:
           COVERALLS_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 

backend/.golangci.yml .golangci.ymlbackend/.golangci.yml renamed to .golangci.yml

@@ -5,17 +5,9 @@ ARG CI
 ARG GITHUB_REF
 ARG GITHUB_SHA
 ARG GIT_BRANCH
-ARG SKIP_TEST
 
 ADD . /build
-WORKDIR /build/backend
-
-# run tests and linters
-RUN \
-    if [ -z "$SKIP_TEST" ] ; then \
-        go test -timeout=30s  ./... && \
-        golangci-lint run ; \
-    else echo "skip tests and linter" ; fi
+WORKDIR /build
 
 RUN \
     version="$(/script/version.sh)" && \
@@ -31,8 +23,8 @@ LABEL org.opencontainers.image.source="https://github.com/ukeeper/ukeeper-readab
 
 RUN apk add --update ca-certificates && update-ca-certificates
 
-COPY --from=build-backend /build/backend/ukeeper-readability /srv/
-ADD ./backend/web /srv/web
+COPY --from=build-backend /build/ukeeper-readability /srv/
+ADD ./web /srv/web
 
 RUN chown -R app:app /srv
 USER app

CLAUDE.md

@@ -41,20 +41,3 @@ services:
     volumes:
       - /tmp/mongodb:/data/db
 
-# uncomment the lines below to have mongodb ready for tests,
-# then start them by running
-# `ENABLE_MONGO_TESTS=true go test ./...`
-#  mongo-tests:
-#    image: mongo:5.0
-#    logging:
-#      driver: json-file
-#      options:
-#        max-size: "20m"
-#        max-file: "5"
-#    hostname: mongo-tests
-#    restart: always
-#    container_name: ureadability-mongo-tests
-#    ports:
-#      - "27017:27017"
-#    environment:
-#      - MONGO_INITDB_DATABASE=admin