Add Panasonic Window Air Conditioner (Hong Kong/Macau) brand

[sam0737]

Proposed change

Adds the brand entry for the new panasonic_window_ac_hk core integration (Panasonic Window Air Conditioner sold in Hong Kong/Macau, controlled over the infrared platform).

This integration is grouped under the existing Panasonic brand, so core_integrations/panasonic_window_ac_hk is a symlink to core_brands/panasonic, reusing the existing Panasonic logo/icon — the same approach already used by panasonic_bluray and panasonic_viera. No new image assets are introduced.

Type of change

• Add a new logo or icon for a new core integration
• Add a missing icon or logo for an existing core integration
• Replace an existing icon or logo with a higher quality version
• Replace an existing icon or logo after a branding change
• Removing an icon or logo

Additional information

• This PR fixes or closes issue: fixes #
• Link to code base pull request: Add Panasonic Window Air Conditioner (Hong Kong/Macau) integration core#172642
• Link to documentation pull request: Add Panasonic Window Air Conditioner (Hong Kong/Macau) integration home-assistant.io#45662
• Link to integration documentation on our website: https://www.home-assistant.io/integrations/panasonic_window_ac_hk

Checklist

• The added/replaced image(s) are PNG
• Icon image size is 256x256px (icon.png)
• hDPI icon image size is 512x512px for (icon@2x.png)
• Logo image size has min 128px, but max 256px, on the shortest side (logo.png)
• hDPI logo image size has min 256px, but max 512px, on the shortest side (logo@2x.png)