feat: rename Docker Watcher to Tinyforge

Rebrand the project as Tinyforge to reflect its evolution from a Docker
container watcher into a self-hosted mini CI/deployment platform.

Rename covers: Go module path, Docker labels, DB/config filenames,
JWT issuer, Dockerfile binary, docker-compose, CI workflows, frontend
i18n, README with static sites docs, and all code comments.

Dockerfile

@@ -22,7 +22,7 @@ COPY . .
 # Copy built frontend into the expected embed location.
 COPY --from=frontend-builder /build/web/build ./web/build
 
-RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o /docker-watcher ./cmd/server
+RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o /tinyforge ./cmd/server
 
 # Stage 3: Minimal runtime image
 FROM alpine:3.19
@@ -34,7 +34,7 @@ RUN addgroup -g 1000 -S app && adduser -u 1000 -S app -G app
 
 WORKDIR /app
 
-COPY --from=backend-builder /docker-watcher /app/docker-watcher
+COPY --from=backend-builder /tinyforge /app/tinyforge
 
 # Data directory for SQLite database.
 RUN mkdir -p /app/data && chown -R app:app /app
@@ -46,4 +46,4 @@ EXPOSE 8080
 ENV DATA_DIR=/app/data
 ENV LISTEN_ADDR=:8080
 
-ENTRYPOINT ["/app/docker-watcher"]
+ENTRYPOINT ["/app/tinyforge"]