Add game data, art, constants and game logic

Add the assignment data set (50 accounts), the logo and vs art, the
constants module, and the pure functions get_random_account,
pick_pair, format_data and check_answer, all with Doxygen comments.
pick_pair never returns the same account twice; check_answer accepts
either choice on a tie. Cover them with pytest tests (22 passing).

The art is built from concatenated raw lines so the backslashes survive
and Doxygen does not read the backticks as markup.

Accept MIL-002 after review RC-005 and add it to the Traceability
Matrix.

Task: MIL-002#1
Task: MIL-002#2
Task: MIL-002#3
Task: MIL-002#4
Task: MIL-002#5
Task: MIL-002#6
Closes #6
Closes #7
Closes #8
Closes #9
Closes #10
Closes #11

docs/milestones/mil-002-game-logic.md

@@ -4,12 +4,13 @@
 | Key | Value |
 | --- | --- |
 | ID | MIL-002 |
-| CrossReference | [BC-001], [PP-001] |
+| CrossReference | [BC-001], [PP-001], [RC-005] |
 
 ## Version History
 | Date | Status | Author | Reviewer | Change | Commit |
 | --- | --- | --- | --- | --- | --- |
-| 2026-10-04 | Proposed | Jens Tirsvad Nielsen | S01 | Initial version | [ddfe96f] |
+| 2026-10-04 | Deprecated | Jens Tirsvad Nielsen | S01 | Initial version | [ddfe96f] |
+| 2026-10-04 | Accepted | Jens Tirsvad Nielsen | S01 | Accepted after review RC-005 | pending |
 
 ---
 
@@ -72,3 +73,4 @@ The assignment data set and art as modules, constants in `constants.py`, and the
 [PP-001]: ../project-plan.md
 [MIL-001]: ./mil-001-project-setup.md
 [ddfe96f]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/014-higher_lower/commit/ddfe96ffa459d5e4b2e30d71bd53878aba2cfc5d
+[RC-005]: ../sqa/reviews/rc-005-mil-002.md