Add shop transactions and karma

[konard]

Fixes #5

Summary

• add persistent character inventories with gold and item rows
• add shop endpoints for buying and selling items by name
• subtract mercenary costs during buy/sell transactions and validate balances
• prevent selling an item that is not present in the character inventory
• add user-level karma with endpoints to increase and decrease it
• add reproducible FastAPI tests using an isolated SQLite database

API changes

• GET /characters/{character_id}/inventory
• POST /characters/{character_id}/inventory/gold/add
• POST /characters/{character_id}/shop/buy
• POST /characters/{character_id}/shop/sell
• POST /me/karma/add
• POST /me/karma/subtract

Testing

• python -m compileall app
• pytest -q

[konard]

Working session summary

Implemented and pushed the fix for issue 5.

PR: #6

What changed:

• Added inventory persistence with gold and item rows.
• Added shop buy/sell endpoints that handle item price plus mercenary cost.
• Prevented selling items that are not in the character inventory.
• Added global user karma with add/subtract endpoints.
• Added requirements.txt, pytest.ini, and API tests covering buy, sell, and karma behavior.
• Updated PR 6 title/body and marked it ready for review.

Verification:

• python -m compileall app
• pytest -q → 3 passed

No CI runs are configured or reported for this branch, and the working tree is clean.

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This summary was automatically extracted from the AI working session output.

[konard]

🤖 Solution Draft Log

This log file contains the complete execution trace of the AI solution draft process.

💰 Cost estimation:

• Model: GPT-5.5
• Provider: OpenAI
• Public pricing estimate: $4.906767

📊 Context and tokens usage:

• 157.4K / 1.1M (15%) input tokens, 11.5K / 128K (9%) output tokens

Total: (157.4K + 2.8M cached) input tokens, 11.5K output tokens, $4.906767 cost

🤖 Models used:

• Tool: OpenAI Codex
• Requested: gpt-5.5
• Model: GPT-5.5 (gpt-5.5)

📎 Log file uploaded as Gist (21680KB)

• View complete solution draft log

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Now working session is ended, feel free to review and add any feedback on the solution draft.

[konard]

✅ Ready to merge

This pull request is now ready to be merged:

• No CI/CD checks are configured for this repository
• No merge conflicts
• No pending changes

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