step 9: single image CI/CD, drop FE/BE split

CI pipeline: replace separate FE + BE image builds with single unified
Dockerfile. Remove FE_IMAGE, FE_REPLICAS, FE_* resource vars. Simplify
build/push/deploy to single IMAGE. Remove frontend.yaml k8s manifest.
Remove provider integration test env vars (PROVIDER, PROVIDER_KEY,
VENICE_API_KEY). Remove EXTRACTION_CONCURRENCY.

Delete server/Dockerfile (backend-only image, superseded by root
Dockerfile). Delete k8s/frontend.yaml (no separate FE deployment).

Update ROADMAP: steps 5-7 and 9 marked complete. Step 8 (ICD) partial.
Step 10 (smoke test + tag) is all that remains for v0.1.0.

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

server/Dockerfile

@@ -1,49 +0,0 @@
-# ==========================================
-# Switchboard Core - Backend Dockerfile
-# ==========================================
-# Standalone Go API server for cluster deployment.
-# Build context is the repo root (not ./server).
-# ==========================================
-
-# Build stage
-FROM golang:1.23-bookworm AS builder
-
-ARG APP_VERSION=dev
-
-WORKDIR /app
-
-# Copy module files and download deps
-COPY server/go.mod server/go.sum* ./
-RUN go mod download
-
-# Copy source and tidy (resolves any go.sum gaps)
-COPY server/ .
-RUN go mod tidy
-
-# Copy VERSION from repo root — used by ldflags and copied to runtime image.
-# If APP_VERSION build-arg was supplied by CI, it takes precedence via ldflags.
-# If not, $(cat VERSION) reads the file directly so the binary always has a real version.
-COPY VERSION ./
-RUN CGO_ENABLED=0 go build -ldflags="-s -w -X main.Version=$(cat VERSION)" -o /bin/switchboard .
-
-# Runtime stage
-FROM debian:bookworm-slim
-
-RUN apt-get update && apt-get install -y --no-install-recommends \
-    ca-certificates \
-    && rm -rf /var/lib/apt/lists/*
-
-COPY --from=builder /bin/switchboard /usr/local/bin/switchboard
-COPY --from=builder /app/database/migrations /app/database/migrations
-
-# VERSION file at /VERSION — version.go init() reads it as fallback for local/dev runs
-COPY --from=builder /app/VERSION /VERSION
-
-# Builtin extensions (seeded into DB on startup)
-COPY extensions/builtin/ /app/extensions/builtin/
-
-WORKDIR /app
-
-EXPOSE 8080
-
-ENTRYPOINT ["switchboard"]