docs: correct temperature conversion documentation

[eman]

Summary

The documentation incorrectly stated that temperature values use a simple +20 offset (e.g., raw + 20, param + 20). The actual encoding is half-degrees Celsius.

What was wrong

Documentation claimed:

• displayed_value = raw_value + 20
• Examples like param=100 for 120°F (implying 100 + 20 = 120)

What is correct

Temperature values are encoded in half-degrees Celsius:

• Formula: fahrenheit = (raw_value / 2.0) * 9/5 + 32
• Inverse: param = (fahrenheit - 32) * 5/9 * 2

Examples:

• 95°F → param = 70 (35°C × 2)
• 120°F → param = 98 (48.9°C × 2)
• 140°F → param = 120 (60°C × 2)
• 150°F → param = 132 (65.6°C × 2)

Files Updated

• docs/guides/reservations.rst - Updated temperature parameter documentation and code examples
• docs/guides/scheduling_features.rst - Fixed temperature encoding documentation
• docs/guides/advanced_features_explained.rst - Replaced "Formula Confirmation" section with correct conversion reference
• docs/protocol/device_features.rst - Updated conversion column references
• docs/protocol/firmware_tracking.rst - Updated conversion examples
• docs/protocol/mqtt_protocol.rst - Fixed temperature encoding notes
• docs/python_api/constants.rst - Updated example conversion
• src/nwp500/models.py - Fixed misleading comment

Validation

• ✅ Linting: All checks passed
• ✅ Type checking: No errors
• ✅ Tests: 126 passed

[Copilot]

Pull request overview

This PR corrects widespread documentation errors regarding temperature encoding in the NWP500 protocol. The documentation incorrectly stated that temperatures use a simple +20 offset, when they actually use half-degrees Celsius encoding with the formula fahrenheit = (raw_value / 2.0) * 9/5 + 32.

Key changes:

• Replaced all raw + 20 references with proper HalfCelsiusToF conversion formula
• Updated temperature examples across all documentation files (e.g., 120°F is param=98, not param=100)
• Fixed code comment in models.py to accurately describe the encoding scheme

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/nwp500/models.py	Corrected misleading comment from "offset (raw + 20)" to "encoded in half-degrees Celsius"
docs/python_api/constants.rst	Changed conversion field from "raw + 20" to "HalfCelsiusToF"
docs/protocol/mqtt_protocol.rst	Updated temperature encoding documentation with correct formula and examples
docs/protocol/firmware_tracking.rst	Replaced raw + 20 conversion references with HalfCelsiusToF
docs/protocol/device_features.rst	Updated conversion column entries and added formula reference
docs/guides/scheduling_features.rst	Fixed temperature parameter encoding section with correct formulas and examples
docs/guides/reservations.rst	Comprehensively updated all temperature-related documentation and code examples
docs/guides/advanced_features_explained.rst	Replaced "Formula Confirmation" section with detailed temperature conversion reference