Add number entity to Liebherr integration

[mettolen]

Proposed change

Added number entity for controlling setpoint temperature to Liebherr integration
Upgraded quality scale to silver as all silver tier items are done

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Deprecation (breaking change to happen in the future)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue:
• Link to documentation pull request: Add number entity to Liebherr integration home-assistant.io#43346
• Link to developer documentation pull request:
• Link to frontend pull request:

Checklist

• I understand the code I am submitting and can explain how it works.
• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the development checklist
• I have followed the perfect PR recommendations
• The code has been formatted using Ruff (ruff format homeassistant tests)
• Tests have been added to verify that the new code works.
• Any generated code has been carefully reviewed for correctness and compliance with project standards.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io

If the code communicates with devices, web services, or third-party tools:

• The manifest file has all fields filled out correctly.
  Updated and included derived files by running: python3 -m script.hassfest.
• New or updated dependencies have been added to requirements_all.txt.
  Updated by running python3 -m script.gen_requirements_all.
• For the updated dependencies a diff between library versions and ideally a link to the changelog/release notes is added to the PR description.

To help with the load of incoming pull requests:

• I have reviewed two other open pull requests in this repository.

[Copilot]

Pull request overview

This PR adds a number entity platform to the Liebherr integration to allow controlling temperature setpoints for fridge/freezer zones. The PR also claims to upgrade the integration from Bronze to Silver quality scale.

Changes:

• Added number platform with temperature setpoint control functionality
• Updated test infrastructure to support platform-specific testing
• Added translations for number entities
• Claimed upgrade to Silver quality scale (but missing implementation)

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
homeassistant/components/liebherr/init.py	Added Platform.NUMBER to PLATFORMS list
homeassistant/components/liebherr/number.py	New number platform implementation for temperature setpoint control
homeassistant/components/liebherr/strings.json	Added translations for number entities and exception messages
homeassistant/components/liebherr/quality_scale.yaml	Marked log-when-unavailable as done (incorrectly)
homeassistant/components/liebherr/manifest.json	Upgraded quality_scale from bronze to silver (prematurely)
tests/components/liebherr/conftest.py	Updated fixtures to support platform-specific testing, added target/min/max to MOCK_DEVICE_STATE
tests/components/liebherr/test_sensor.py	Updated to use platforms fixture parameter
tests/components/liebherr/test_number.py	New comprehensive test file for number platform
tests/components/liebherr/snapshots/test_number.ambr	Snapshot tests for number entities