feature: add display_num configuration for report generation

[WCY-dt]

Description

• add display_num configuration for report generation

Fixes #4

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation

[Copilot]

Pull Request Overview

This PR adds a configurable display_num parameter that allows users to control how many service status entries are displayed in the HTML report. The feature replaces hardcoded values with dynamic configuration.

Key changes:

• Added display_num configuration field with proper default handling
• Updated report generation functions to accept and use the configurable display number
• Moved responsive CSS from static file to template with dynamic breakpoints

Reviewed Changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
internal/types/structures/configure/configure.go	Added DisplayNum field to configuration structure
internal/types/types/default_config/default_config.go	Added SetDefaultDisplayNum function for default value handling
internal/configure/config.go	Integrated display_num into default configuration setup
internal/types/structures/reporter/utils.go	Updated functions to accept displayNum parameter instead of using hardcoded values
internal/reporter/report.go	Modified GetReport and WriteReport to accept and use displayNum parameter
cmd/ponghub/main.go	Updated function calls to pass cfg.DisplayNum
cmd/ponghub/main_test.go	Updated test function calls to pass cfg.DisplayNum
templates/report.html	Added inline CSS with dynamic DisplayNum values for responsive design
static/style.css	Removed hardcoded CSS values that are now dynamically generated
README.md	Added documentation for the new display_num configuration option
README_CN.md	Added Chinese documentation for the new display_num configuration option

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