fix: decouple lint stage from web-builder in Dockerfile

Remove COPY --from=web-builder from the lint stage so it can run
independently and fail fast. Create placeholder files for the
go:embed directive instead. The build stage still uses the real
SPA assets from web-builder.

Update README to reflect that lint no longer depends on web-builder.

Dockerfile

@@ -15,7 +15,9 @@ WORKDIR /src
 COPY go.mod go.sum ./
 RUN go mod download
 COPY . .
-COPY --from=web-builder /web/dist/ web/dist/
+# Create placeholder files so //go:embed dist/* in web/embed.go resolves
+# without depending on the web-builder stage (lint should fail fast)
+RUN mkdir -p web/dist && touch web/dist/index.html web/dist/style.css web/dist/app.js
 RUN make fmt-check
 RUN make lint
 

README.md

@@ -1854,9 +1854,11 @@ The Dockerfile is a four-stage build:
 1. **web-builder**: Installs Node dependencies and compiles the SPA (JSX →
    bundled JS via esbuild) into `web/dist/`
 2. **lint**: Runs formatting checks and golangci-lint against the Go source
-   (with the built SPA assets copied in)
+   (uses empty placeholder files for `web/dist/` so it runs independently of
+   web-builder for fast feedback)
 3. **builder**: Runs tests and compiles static `neoircd` and `neoirc-cli`
-   binaries (CLI built to verify compilation, not included in final image)
+   binaries with the real SPA assets from web-builder (CLI built to verify
+   compilation, not included in final image)
 4. **final**: Minimal Alpine image with only the `neoircd` binary
 
 ### Binary