RFR: 6004: Should add tenuring summary to the GC visualization [v2]

[Marcus Hirt]

On Thu, 23 Oct 2025 14:35:54 GMT, Aymane Harmaz <aharmaz at openjdk.org> wrote:

>> This change adds a new tab to display the tenuring distribution for GC cycles.
>> 
>> There are 3 case scenarios:
>> - Single GC cycle selected: A histogram chart is shown representing the tenuring distribution (total size across ages) for the selected cycle.
>> - No GC cycle selected: An informational message is displayed to prompt the user to select a cycle.
>> - Multiple GC cycles selected: An informational message is displayed indicating that only a single cycle can be viewed at a time.
>> This enhancement improves visibility into object tenuring during individual GC cycles. 
>> 
>> <img width="1174" height="599" alt="Screenshot 2025-10-15 at 16 51 19" src="https://github.com/user-attachments/assets/76ce69c2-60eb-48c8-be9f-6387cbfa7c42" />
>> 
>> <img width="1174" height="599" alt="Screenshot 2025-10-15 at 16 51 34" src="https://github.com/user-attachments/assets/a5fc9bc9-fa72-42c9-aeb2-ecad21e4ac66" />
>> 
>> <img width="1174" height="599" alt="Screenshot 2025-10-15 at 16 51 57" src="https://github.com/user-attachments/assets/63ffba47-8e08-430a-9a28-11473b59e6dc" />
>
> Aymane Harmaz has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Implemented review comments

Marked as reviewed by hirt (Lead).

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PR Review: https://git.openjdk.org/jmc/pull/679#pullrequestreview-3530851144