Add Inventory Module

[Mkalbani]

Description

Create an inventory module that manages items (tools, tokens) a player collects during gameplay.

Acceptance Criteria

• An inventory module exists under src/inventory/mod.rs
• Inventory struct holds a list of Item with id, name, and quantity
• Items can be added, removed, and queried
• Inventory can be serialized for persistence
• Unit tests cover add, remove, overflow, and empty cases

[ayomideadeniran]

I'm a full-stack developer and I'd like to take this issue.
I understand the requirements and will follow the existing project structure, keep the implementation clean, and include proper tests where applicable.

ETA: 1–3 days (depending on scope)
Portfolio: https://knightsdev-portfolio.vercel.app/

[devfoma]

Hi there, i am a software engineer that loves solving problem and providing solutions. This sounds like a challenge i would like to take on. Kindly assign and i wont disappoint.

[grantfox-oss]

🦊 GrantFox — @devfoma has been assigned to this issue as part of the Official Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #17)
2. Your PR will be reviewed by the MindFlowInteractive maintainers

Good luck! Track your progress on GrantFox.