feat(git-stacks): support multi-file compose deployment

[jakob1379]

Proposed change

Adds support for Docker Compose multi-file Git stack deployments.

Git stacks can now store and deploy an ordered list of compose files, preserving the existing single-file composePath
behavior for backwards compatibility. Deployment, sync, source copying, Hawser payloads, and stack source tracking now pass
the full compose file list through to Docker Compose in order.

Also includes:

• SQLite and PostgreSQL migrations for compose_paths.
• Shared compose path normalization helper.
• Basic regression test for compose path normalization.
• Cleanup ignores for generated build/output artifacts.

Testing:

• bun test tests/compose-paths.test.ts
• NODE_OPTIONS=--max-old-space-size=4096 npx vite build
• git diff --check

Closes #N/A

Type of change

• Bug fix: non-breaking change which fixes an issue.
• New feature / Enhancement: non-breaking change which adds functionality.
• Breaking change: fix or feature that would cause existing functionality to not work as expected.
• Other. Please explain:

[CLAassistant]

All committers have signed the CLA.

[jakob1379]

This is meant as a starting point for collaboration, rather than a finished proposal.

[jakob1379]