Fix seeder: install tsx globally, add verbose CMD output

- Install tsx globally to avoid lockfile conflicts with --omit=dev
- Use set -ex in CMD so Docker logs show exactly which step fails
- Production deps installed cleanly via npm ci --omit=dev

Co-authored-by: Cursor <cursoragent@cursor.com>

Dockerfile.seed

@@ -7,10 +7,12 @@ FROM node:20-alpine
 
 WORKDIR /app
 
-# Install only production deps (skip sharp & other heavy devDeps),
-# then add tsx separately so we can run TypeScript seed scripts.
+# Install tsx globally (isolated from project deps, avoids lockfile conflicts)
+RUN npm install -g tsx
+
+# Install only production deps (no sharp or other heavy native devDeps)
 COPY package*.json ./
-RUN npm ci --omit=dev && npm install --no-save tsx
+RUN npm ci --omit=dev
 
 # Copy only what the seed scripts need
 COPY scripts/ ./scripts/
@@ -21,4 +23,5 @@ COPY tsconfig.json ./
 ENV RELAY_URL=ws://relay:8080
 ENV ORIGIN=http://localhost:7777
 
-CMD ["sh", "-c", "node scripts/wait-for-relay.mjs && npx tsx scripts/seed-profiles.ts && npx tsx scripts/seed-activity.ts && echo '✅ Seeding complete!'"]
+# set -ex: print each command before running, exit on first failure
+CMD ["sh", "-c", "set -ex && node scripts/wait-for-relay.mjs && tsx scripts/seed-profiles.ts && tsx scripts/seed-activity.ts && echo 'Seeding complete!'"]