Add missing filter options to product search endpoint

[HelgeSverre]

Summary

This PR adds support for all missing API parameters in the product_search method to achieve complete parity with the Kassal.app /products endpoint.

New Filter Options Added

• store - Filter products by store codes (e.g., "SPAR_NO", "MENY_NO")
• has_labels - Filter products by labels (e.g., ["euroleaf", "frysevare"])
• category - Filter products by category name (e.g., "dairy")
• category_id - Filter products by category ID

Changes Made

Client Library (kassalappy/client.py)

• Added 4 missing parameters to product_search() method
• Updated parameter dictionary and docstrings
• Maintains full backward compatibility

CLI Enhancement (kassalappy/cli.py)

• Added --store option with PhysicalStoreGroup validation
• Added --category option for category filtering
• Both options integrate seamlessly with existing CLI

Test Coverage (tests/)

• Created comprehensive product search fixture
• Added 5 new test cases covering all filtering scenarios
• Tests validate basic search, store filtering, category filtering, label filtering, and combined filters

Documentation

• Added CLAUDE.md with development guidance
• Updated all docstrings with parameter descriptions

Testing

✅ Unit Tests: All 6 tests pass (including original + 5 new product search tests)

✅ Real API Testing: Verified with actual Kassal.app API:

• Store filtering works correctly (store="SPAR_NO" returns only SPAR products)
• Category filtering functions as expected
• Basic search returns products from multiple stores

✅ CLI Testing: Command-line interface verified working:

kassalappy product "milk" --store SPAR_NO --count 2

Usage Examples

Programmatic Usage

# Filter by store
products = await client.product_search(search="milk", store="SPAR_NO")

# Filter by category  
products = await client.product_search(search="bread", category="bakery")

# Filter by labels
products = await client.product_search(search="milk", has_labels=["euroleaf"])

# Combined filters
products = await client.product_search(
    search="milk", 
    store="MENY_NO", 
    category="dairy",
    has_labels=["euroleaf"]
)

CLI Usage

# Filter by store
kassalappy product "milk" --store SPAR_NO

# Filter by category
kassalappy product "bread" --category bakery

# Combined filters
kassalappy product "milk" --store MENY_NO --category dairy

This implementation provides complete access to the Kassal.app API's filtering capabilities while maintaining backward compatibility.

🤖 Generated with Claude Code

[HelgeSverre]

TL;DR: claude la til noen nye filtervalg på produktsøk-funksjonen.