feat(compose): suggest compose files from the selected GitHub branch

[agentHits]

What

The Compose Path field of a GitHub compose service is now a combobox: you can still type a path, and a list under the field shows the compose files that exist in the selected branch. Typing filters the list; clicking or Arrow keys + Enter picks a file.

• New query github.getGithubComposeFiles (owner, repo, branch, githubId). It resolves the branch, reads its tree in one recursive call and returns files whose name contains compose and ends in .yml/.yaml, as ./path, shallowest first.
• Access to the git provider is checked before the tree is read, same as getGithubBranches; registered as read in procedure access.
• A missing branch or empty repository (404) returns an empty list; other GitHub errors pass through.
• Enter keeps submitting the form until a file is highlighted, so it does not silently replace the current path.
• Form label, description and error ids are passed to the input.

Only GitHub gets the list for now; GitLab, Gitea and Bitbucket keep the plain input.

Tests

• __test__/git-provider/github-compose-files.test.ts: filtering and order, branch-name lookup with slashes, 404 → empty list, other errors pass through, compose name matcher.
• provider-router-security.test.ts: the query is rejected before the tree is read when provider access is denied.
• Locally: typecheck of apps/dokploy and packages/server, biome, git-provider/permissions/api/security/compose test folders (695 tests) pass.
• Not checked in a browser yet: needs a panel with a real GitHub App.

🤖 Generated with Claude Code