Fix Docker build: include scripts directory and tsx runtime

Problem: Docker container failed to start with REGENERATE_GIFS=true
because scripts directory was not copied to production image and tsx
was not available at runtime.

Error:
  Cannot find module '/app/packages/backend/scripts/regenerate-all-gifs.ts'

Root cause:
1. Dockerfile only copied dist/ and prisma/ directories, not scripts/
2. tsx was in devDependencies, not available in production

Solution:
1. Add COPY scripts directory in Dockerfile (line 69)
2. Move tsx from devDependencies to dependencies in package.json
3. Update pnpm-lock.yaml to reflect dependency change

Changes:
- Dockerfile: Added COPY --from=backend-builder scripts directory
- package.json: Moved tsx@^4.7.0 to dependencies
- pnpm-lock.yaml: Updated lockfile

This allows the REGENERATE_GIFS environment variable to work correctly
in production, enabling automatic GIF regeneration on container startup.

Co-Authored-By: Auggie

pnpm-lock.yaml

@@ -59,6 +59,9 @@ importers:
       passport-microsoft:
         specifier: ^1.0.0
         version: 1.1.0
+      tsx:
+        specifier: ^4.7.0
+        version: 4.21.0
       zod:
         specifier: ^3.22.4
         version: 3.25.76
@@ -102,9 +105,6 @@ importers:
       prisma:
         specifier: ^5.8.1
         version: 5.22.0
-      tsx:
-        specifier: ^4.7.0
-        version: 4.21.0
       typescript:
         specifier: ^5.3.3
         version: 5.9.3