feat: add git worktree support to create-branch command

[TellMeAlex]

• Add --worktree and --worktree-path flags to create-branch command
• Implement CreateWorktree, ListWorktrees, and RemoveWorktree in GitProvider
• Add Worktree domain model to represent git worktree state
• Add createWorktreeBranch use case method with default path generation
• Add comprehensive unit tests for git worktree operations
• Add integration tests for worktree creation workflow
• Update documentation with worktree usage examples and benefits
• Support fork context (upstream/origin) for worktree creation

Closes #146

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[danielfn]

@TellMeAlex thank you for your contribution!

Not sure why, but the PR-verify workflow did not run with your commit. Trying it locally, I see there are errors with gofmt, could you fix them (make fmt) and push again to trigger the CI?

[TellMeAlex]

Hi @danielfn, thanks for the feedback! I've already applied gofmt formatting and pushed the changes. However, I notice the CI is still failing. Could you help me identify what else might need to be fixed?

[danielfn]

Hi @danielfn, thanks for the feedback! I've already applied gofmt formatting and pushed the changes. However, I notice the CI is still failing. Could you help me identify what else might need to be fixed?

@TellMeAlex there is a failure in the tests, mocks may need to be updated:

-: # github.com/InditexTech/gh-sherpa/internal/fork [github.com/InditexTech/gh-sherpa/internal/fork.test]
Error: internal/fork/fork_test.go:116:43: cannot use gitProvider (variable of type *mockGitProvider) as domain.GitProvider value in argument to NewManager: *mockGitProvider does not implement domain.GitProvider (missing method CreateWorktree)