Add planning baseline: business case, stakeholders, plan, milestones and reviews

Mount the SQA/QC framework and add BC-001, SA-001, PP-001, MIL-001 to
MIL-008, review records RC-001 to RC-010 and the traceability matrix.
Task: MIL-001#1
Task: MIL-001#2

docs/business-case.md

@@ -0,0 +1,166 @@
+# Business Case
+
+## Metadata
+| Key | Value |
+| --- | --- |
+| ID | BC-001 |
+| CrossReference | [SA-001], [PP-001] |
+| Language | en |
+| Domain | it |
+
+## Version History
+| Date | Status | Author | Reviewer | Change | Commit |
+| --- | --- | --- | --- | --- | --- |
+| 2026-10-13 | Accepted | Jens Tirsvad Nielsen | AI as stand-in for S01 | Initial version | pending |
+
+---
+
+## Executive Summary
+
+Day 23 of Udemy's "100 Days of Code: The Complete Python Pro Bootcamp" is the
+second capstone: a Turtle Crossing game in the style of Crossy Road. The player
+steers a turtle north across a multi-lane road of randomly generated cars; each
+crossing raises the level and the car speed, and a collision ends the game.
+This project delivers the game as a small, readable, tested Python repository
+with no runtime dependencies, so that course participants can run and compare
+it and GitHub visitors can browse it for ideas.
+
+## Methodological and Standards Foundation
+
+- Object-oriented design with one class per concern (`Player`, `CarManager`,
+  `Scoreboard`), using the assignment's names.
+- Quality characteristics follow ISO/IEC 25010:2023, as the QC checklists of
+  the SQA framework tag them.
+- Source is documented with Doxygen comments and built with a `Doxyfile`.
+- Work follows the software quality assurance (SQA) and quality control (QC) framework mounted at `framework/`: plan first,
+  review each artifact, one pull request per milestone.
+
+## Problem Statement
+
+The course supplies four stub files and a video walkthrough, but no
+repository that a participant can clone, run, test and read. Solutions shared
+between coursists are single files without tests, run instructions or a
+statement of the Python version they need, and cars are drawn as plain colour
+blocks.
+
+## Business Opportunity
+
+A well-structured reference solution gives S02 a runnable comparison point and
+gives S03 a clear example of a small Python project with tests, continuous integration (CI),
+documentation and a multilingual wiki, at no dependency cost.
+
+## Objectives
+
+1. Deliver the game behaviour of the Day 23 assignment at Normal difficulty
+   (all steps): forward-only turtle, random cars moving left, level-up with
+   speed increase, collision stop, scoreboard and GAME OVER.
+2. Draw each car so it reads as a car (body, cabin, wheels), not a colour
+   block, while keeping the 20 x 40 px footprint the assignment specifies.
+3. Provide `src/`, `tests/` and `docs/` with pytest tests for the game logic
+   and no runtime dependencies beyond the Python standard library.
+4. Provide a README from the agreed template, a local `.venv` guide, a
+   `Doxyfile`, CI and a wiki in English, Danish and Bahasa Malaysia.
+5. Publish the repository with a description and topics.
+
+## Scope
+
+### In Scope
+
+- Player, car manager and scoreboard classes, `constants.py`, `main.py`.
+- Car appearance drawn with the standard `turtle` module only.
+- Unit tests for the logic that does not need a display.
+- `pyproject.toml` (Python 3.13 or newer), Python `.gitignore`, Doxygen
+  comments and `Doxyfile`.
+- README, CI workflow, wiki pages in `en`, `da` and `ms`.
+- Repository description and topics on the git host.
+
+### Out of Scope
+
+- Sound, images, sprite files or any third-party package at runtime.
+- Menus, difficulty selection, high-score persistence, networking.
+- Packaging for PyPI.
+- Re-implementing the Hard and Expert course variants.
+
+## Expected Benefits
+
+### Tangible Benefits
+
+- A cloneable repository that runs with one command after the venv is set up.
+- A passing automated test suite and a CI run on every pull request.
+- Generated source documentation for the three classes.
+
+### Intangible Benefits
+
+- A readable example S02 can compare their own solution against.
+- A documented course portfolio item for S01 with a visible review trail.
+
+## Strategic Alignment
+
+This is one project in the 100 Days of Code portfolio. It demonstrates the
+same planning, review and pull-request discipline across the whole series.
+
+## Success Criteria
+
+| # | Criterion | Target | Measure |
+| --- | --- | --- | --- |
+| 1 | Game plays as the assignment describes | All five Step 2 behaviours work | Manual play-through checklist in the final milestone |
+| 2 | Cars look like cars | Each car shows a body, cabin and two wheels, 40 x 20 px | Visual check in the Cars milestone |
+| 3 | Tests pass | 100 % of tests pass on Python 3.13 | `pytest` exit code 0 locally and in CI |
+| 4 | No runtime dependencies | Zero entries under `dependencies` | `pyproject.toml` inspection |
+| 5 | Run instructions work | A fresh clone runs following the README on Windows, Linux and macOS sections | S01 follows the README on a clean clone |
+| 6 | Wiki in three languages | Every wiki page exists in `en`, `da`, `ms` | File listing of the wiki |
+| 7 | Repository metadata | Description and at least 5 topics set | Repository page |
+
+## Risks
+
+| Risk | Impact | Mitigation |
+| --- | --- | --- |
+| Turtle needs a display, so CI and tests cannot open a window | Tests cannot cover rendering | Keep game logic free of the screen where possible; test it against a stub; verify rendering manually |
+| Custom car shape renders differently across platforms | Cars look wrong for some viewers | Use `turtle.register_shape` with polygons only; check on Windows first and note limits in the README |
+| Python 3.13 tkinter missing on some Linux installs | Participants cannot run the game | Document `python3-tk` in the Linux Debian section |
+| Tokens in `.env` end up in the repository | Credential leak | `.env` in `.gitignore` before the first commit that adds files; the file is never read by project code |
+| Scope creep from "nice to have" features | Delay | Out of Scope list; changes need a Business Case amendment |
+
+## Assumptions
+
+- S01 is Product Owner, developer and reviewer; reviews are not independent
+  (supervised mode).
+- The idea is a hunch, not validated by behaviour, and is cheap to build, so no
+  riskiest-assumption test is run.
+- S01 can reach S02 and S03 through the git host and the course forum.
+- The git host `git.tirsystem.com` is available for the repository and wiki.
+- S01 stated no deadline; the plan assumes two weeks (see PP-001 Open Issues).
+
+## Constraints
+
+- Python 3.13 or newer, a local `.venv`, pytest for tests.
+- Constants live in `constants.py`; configuration lives in `pyproject.toml`.
+- Layout is `src/`, `tests/` and `docs/`.
+- Only the standard library at runtime.
+
+## Cost–Benefit Assessment
+
+Qualitative: the project is a learning exercise with no budget.
+
+| Costs | Benefits |
+| --- | --- |
+| S01's time: about two weeks of evening work | Portfolio item, a reusable project template, a shareable solution |
+| Review effort (S01 reviews own work) | Documented planning and review trail |
+
+## Stakeholders
+
+| Stakeholder ID (SA) | Interest in this project |
+| --- | --- |
+| S01 | Product Owner, developer and reviewer; wants a finished, well-planned portfolio piece |
+| S02 | Udemy coursists; want readable, runnable code with the assignment's names and run instructions |
+| S03 | GitHub viewers; want a clear description, topics and README, and no runtime dependencies |
+
+## Recommendation
+
+Proceed — the scope is small, cheap and fully specified by the course, and it
+serves all three stakeholders.
+
+---
+
+[SA-001]: ./stakeholder-analysis.md
+[PP-001]: ./project-plan.md