Plan RepoFoundry: business case, stakeholders, plan, milestones, UC-001

Add the planning baseline for RepoFoundry (create-project.sh), which
creates GitHub and Gitea repositories, a Gitea -> GitHub push mirror and
a local project with the SQA-QC-Framework.

- BC-001 Business Case and SA-001 Stakeholder Analysis (S01, S02, S03)
- PP-001 Project Plan: three phases, 2026-10-05 to 2026-11-13 (proposed)
- MIL-001 Foundation, MIL-002 Repositories and Mirror,
  MIL-003 Scaffold and Release, with 18 task rows
- US-001, UC-001 "Create a new project" and SSD-001
- Registry: PO language en; PP, MIL, US, UC and SSD rows added

Decisions recorded: origin uses HTTPS from GITEA_URL unless the SSH test
on port 10022 passes; S01 and S02 are held by one person for now.

Refs: no issues synced yet (sync-project.sh dry run only)

docs/uc-001/uc.md

@@ -0,0 +1,82 @@
+# Create a new project
+
+## Metadata
+| Key | Value |
+| --- | --- |
+| ID | UC-001 |
+| CrossReference | [US-001], [SA-001] |
+
+## Version History
+| Date | Status | Author | Reviewer | Change | Commit |
+| --- | --- | --- | --- | --- | --- |
+| 2026-10-05 | Proposed | Jens Tirsvad Nielsen | S02 | Initial version | pending |
+
+---
+
+**Format:** Fully Dressed
+
+## Fully Dressed
+
+- **Scope:** RepoFoundry (`create-project.sh`)
+- **Level:** user-goal
+- **Primary Actor:** Maintainer (S01 or S02; one person holds both roles for now)
+- **Stakeholders and Interests:**
+  - S01 — new projects start from one repeatable, correct setup
+  - S02 — credentials are never exposed and nothing is overwritten silently
+  - S03 — the published procedure is documented and reusable
+- **Preconditions:**
+  - `config.env` and `.env` exist and are valid.
+  - `git` and `curl` are installed.
+  - The Maintainer has a GitHub PAT, a Gitea token and SSH access to Gitea on port 10022.
+- **Postconditions (success guarantee):**
+  - An empty repository exists on GitHub and on Gitea under the chosen owners.
+  - The Gitea repository is a push mirror to GitHub.
+  - A local project directory exists with credential-free remotes `origin` (Gitea) and `github`, the `framework` submodule, installed skills and hooks, and the copied templates.
+  - The Maintainer has a summary of what was created.
+
+### Main Success Scenario
+
+1. The Maintainer starts the project creation.
+2. The system loads and validates the configuration and credentials and checks that the required tools exist.
+3. The Maintainer provides the repository name, description, visibility, the GitHub owner, the Gitea owner, the local directory, and whether to enable the plan gate.
+4. The system checks that both tokens work, that the owners accept new repositories, that the name is free on both hosts, and whether SSH to Gitea works.
+5. The system creates the empty GitHub repository.
+6. The system creates the empty Gitea repository.
+7. The system configures the Gitea repository as a push mirror to GitHub and verifies it.
+8. The system creates the local project with the `origin` and `github` remotes.
+9. The system adds the framework submodule, installs its skills and hooks (and the plan gate if chosen) and copies the templates.
+10. The system reports a summary of what was created.
+
+### Extensions (Alternative / Exception Flows)
+
+- 2a. A required tool is missing, or a configuration value is missing or malformed:
+  1. The system stops before any change and names the problem without showing a credential.
+- 4a. A token is invalid, an owner does not accept the repository, or the name is taken:
+  1. The system stops before creating anything and says which check failed.
+- 4b. SSH to Gitea does not work:
+  1. The system uses HTTPS for `origin` and warns that the framework submodule step will fail until SSH is configured.
+- 5a, 6a, 7a. A step fails after an earlier one succeeded:
+  1. The system stops and reports what exists, what failed and how to continue.
+- 8a, 9a. The target directory or a target file already exists:
+  1. The system asks the Maintainer before replacing it; on no, it skips that item and reports it.
+- 9b. A different `core.hooksPath` is already set:
+  1. The system asks before replacing it.
+
+### Special Requirements / Business Rules
+
+| Step | Rule |
+| --- | --- |
+| 2, 4 | A token never appears in output, logs, command lines, remote URLs or temporary files left behind |
+| 3 | The GitHub owner and the Gitea owner are chosen separately; `GITHUB_USER` is only the authenticating account |
+| 7 | The mirror direction is Gitea to GitHub |
+| 8 | `origin` uses HTTPS derived from `GITEA_URL`, or SSH when the SSH test in step 4 passed |
+| 8, 9 | Nothing is overwritten or deleted without consent, and no commit is made |
+
+### Open Issues
+
+- The exact SSH `origin` URL form (port 10022) is settled in MIL-003.
+
+---
+
+[US-001]: ../user-stories.md
+[SA-001]: ../stakeholder-analysis.md