fix: clarify project setup onboarding

[EmadHelmi]

Summary

• allow GitHub and GitLab solo setup before a repository URL exists
• report safe virtual-environment prompt recreation steps after apply
• separate package authorship from Git identity and signing guidance
• make Getting Started the single ordered setup walkthrough
• prepare version 1.0.1

Motivation

New projects may be customized before their hosted repository exists, and users need one unambiguous setup path with explicit environment and Git identity steps.

Testing

• uvx --from uv==0.12.7 uv lock --check
• uv run pre-commit run --all-files
• uv run pre-commit run --all-files --hook-stage pre-push
• uv build
• independent review completed; all findings corrected and the full quality gate rerun

Checklist

• I kept this pull request focused on one coherent change.
• I ran the relevant local quality checks.
• I added or updated tests for changed behavior when applicable.
• I updated documentation or confirmed that no documentation change is needed.
• I verified that the change contains no secrets or private data.
• I agree that my contribution may be distributed under the MIT License.