Add Core Keeper game support

[ChaiyoKung]

Resolve #46

What does this PR do?

Adds Core Keeper as a supported game, following the existing multi-game structure (GameRegistry + per-game instruments/layouts/settings).

Changes

Game support

• Register Core Keeper in GameRegistry with process detection (CoreKeeper) and per-game location / active-state settings
• Add CoreKeeperLocation and ActiveCoreKeeper user settings, including the default mirrors in App.config
• Add 6 instruments — Pocket Piano, Cello, Drumkit, Flute, Harp, Ocarina — one file per instrument under Core/Games/CoreKeeper/Instruments/, mirroring the Heartopia structure
• All instruments share a 24-key chromatic QWERTY layout matching the in-game instrument keybinds (top row q2w3er5t6y7u, bottom row zsxdcvgbhnjm). Each instrument sounds in its own octave range: Drumkit/Cello C2–B3, Harp/Pocket Piano C3–B4, Flute C4–B5, Ocarina C5–B6 (top row = upper octave, bottom row = lower octave)
• Add the game icon (256×256)

Docs & housekeeping

• README: add Core Keeper to the supported games list, refresh the multi-game feature line to cover all registered games, add a ban-risk note for Core Keeper, and credit Pugstorm in the trademark attributions
• Bug report template: add Core Keeper to the game dropdown, plus previously missing games; quote dropdown entries containing colons for valid YAML

Testing

• dotnet build passes with 0 errors
• dotnet format --verify-no-changes clean on all touched C# files
• Process name (CoreKeeper) verified from Task Manager with the Steam version running
• Keybinds verified against the in-game instrument UI, including the per-instrument sounding ranges above; keys are consumed as notes only while the instrument screen is open (no movement/hotbar conflicts)
• Core Keeper supports held notes and chords, which matches the app's key down/up playback model
• Live end-to-end playback test in-game with the build from this branch — works as expected

Tested with Core Keeper v1.2.1.5 (Steam), Windows 11.

Demo videos (per instrument)

Each video shows a MIDI file played by Auto MIDI Player into the corresponding in-game instrument:

Instrument	Sounding range	Demo
Drumkit	C2–B3	https://github.com/user-attachments/assets/e62d8266-f8d2-4375-8761-29d1d4d198e6
Cello	C2–B3	https://github.com/user-attachments/assets/5a109168-c06e-4ea5-ad93-ea357bf2ddcd
Harp	C3–B4	https://github.com/user-attachments/assets/5de3b8f0-2bab-441f-a5f9-556fadb8e252
Pocket Piano	C3–B4	https://github.com/user-attachments/assets/5aea0f40-3aca-4224-a8eb-117ed7fd1747
Flute	C4–B5	https://github.com/user-attachments/assets/0edfd5fe-7145-43e9-8211-a069d10a461b
Ocarina	C5–B6	https://github.com/user-attachments/assets/867404c2-7733-474b-96a2-2c928263a4e0

Notes for reviewers

• Instruments and layouts are auto-discovered via reflection from the AutoMidiPlayer.WPF.Core.Instruments namespace, so no central registration list needed updating
• Since each instrument has its own octave range, out-of-range notes (below C2 / above B6) rely on the existing per-song transpose, same as other supported games
• Version bump: intentionally left out of this PR. Per CONTRIBUTING.md this change would warrant a SemVer minor bump (7.11.4 → 7.12.0, matching how previous game additions were versioned — e.g. Harry Potter: Magic Awakened bumped 7.7.0 → 7.8.0 in its support commit), but I'd rather leave versioning decisions to you. Happy to bump it if you'd like — just let me know!
• This branch also carries a small docs fix (docs: update .NET version to 10.0 and fix license file references) — happy to rebase it out if you'd prefer to keep this PR game-only

Happy to adjust anything — mapping, instrument structure, or docs wording. Thanks for the great project! 💖