fix: restaurant info update in manager panel

[kingazm]

📄 Pull Request Description

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Important: this PR will not work without this one: JUCanEat/java-backend#85

🧩 What was changed?

• Fixed bug causing issues with updating description or opening hours for restaurant
• Extended opening hours functionality in UI to allow to update opening hours separately for each day, and display this data
• Moved some interfaces to interfaces file to improve code readability

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💡 Why was it changed?

#107
#108

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⚙️ How was it implemented?

• Refactored the restaurant opening hours UI to allow both "same hours every day" and per-day editing.
• Updated the modal to use a responsive, modern layout with compact time fields that remain on the same row on mobile.
• Ensured all time fields can be left empty, supporting closed days without a separate checkbox.
• Updated the facility info box to display opening hours in a compact, two-column layout, with accurate handling of days with no hours set.

Maintained current coding practices and used already introduced frameworks.

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⚠️ Side Effects or Risks

None that I am aware of, except for restaurant updates working better:)

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✅ Checklist

• All 4 sections above are clearly filled out
• Tests and documentation updated