fix(mana-sync): update Dockerfile to copy workspace shared-go dependency

The Dockerfile only copied services/mana-sync, but go.mod has a replace
directive pointing to ../../packages/shared-go which needs to be in the
build context. Switch context to repo root and copy both packages.

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

docker-compose.macmini.yml

@@ -535,8 +535,8 @@ services:
 
   mana-sync:
     build:
-      context: services/mana-sync
-      dockerfile: Dockerfile
+      context: .
+      dockerfile: services/mana-sync/Dockerfile
     image: mana-sync:local
     container_name: mana-core-sync
     restart: always

services/mana-sync/Dockerfile

@@ -2,10 +2,15 @@
 FROM golang:1.25-alpine AS builder
 
 WORKDIR /app
-COPY go.mod go.sum ./
-RUN go mod download
 
-COPY . .
+# Copy workspace dependency first (replace directive in go.mod)
+COPY packages/shared-go ./packages/shared-go
+
+# Copy mana-sync source
+COPY services/mana-sync ./services/mana-sync
+
+WORKDIR /app/services/mana-sync
+RUN go mod download
 RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o /mana-sync ./cmd/server
 
 # Runtime stage