Fix existing bugs in the project

[Nazarii-31]

@github-actions
Fix the Mock Data Generator UI implementation to match the screenshot.

1. Create a new MockDataController and views that:

   • Display user profiles with name, email, title, department, time zone, and working hours
   • Allow setting calendar generation range (1 week selector)
   • Include meeting density selector (low/medium/high)
   • Implement action buttons: Reset to Default, Generate Random Data, Regenerate Calendar Events, Export Data

2. Create a clean implementation of MockCalendarGenerator.cs service that:

   • Generates calendar data based on user profiles
   • Adjusts meeting density based on selection
   • Avoids nested if/else chains
   • Uses a data-driven approach

3. Update the view to display generated data in a clean, structured format

Focus on simplicity and avoiding complex conditional logic. Use pattern matching and LINQ instead of nested conditionals.

Route these properly with attribute routing:
[Route("api/mock-data")]
[ApiController]

@github-actions
Fix the bot's language and slot display issues:

1. Update the slot response formatting to:

   • Always use English language (fix Russian responses like "пятница" and "среда")
   • Format dates consistently (e.g., "Friday, Aug 2 at 1:00 PM - 2:00 PM")
   • Group slots by day with clear headings

2. Fix the slot finding logic to:

   • Only show slots for the specifically requested days (when asking for Friday, don't show Wednesday)
   • When "next week" is requested, show slots across multiple weekdays, not just Thursday

Implement this without complex nested conditionals. Use a clean approach that formats the results directly from the data model.

Key files to modify:

• The service that generates slot responses
• The formatting logic for slot display

@github-actions
Add participant availability information to slot responses:

1. Enhance the slot finding response to include:

   • Total number of participants available for each slot
   • List of available participants for each slot
   • List of unavailable participants with their conflicts
   • Visual indicator (✅/⚠️) for full vs. partial availability

2. Update the slot response formatter to:

   • Show "All participants available" when everyone can attend
   • Show "3/5 participants available" with names when partial
   • Include unavailable participants: "Unavailable: John (Meeting with Client), Jane (Vacation)"

3. Modify the MockCalendarGenerator to properly track conflicts

Implementation must be clean and avoid excessive conditional logic.