[GSoC 2026] docs(chatbot): document the job verdict

[berardifra]

Follow-up to intelowlproject/IntelOwl#3898, which is merged into develop: the chatbot now reports
IntelOwl's own reconciled verdict on a job, and the chatbot page did not describe it.

What changes

• "What it can do" — the summarize bullet now mentions the verdict, which is the substantive new
  capability rather than a detail of the summary.
• Quick actions — the two job chips "Summarize this job" and "Evaluate results" were collapsed
  into a single "Summarize & evaluate", because both now reach the same tool and returned the
  same answer. The listed chips were stale.
• New section "The verdict on a job" — what the verdict is, where it comes from, and what happens
  when there is none.
• One extra example question ("Is job #1234 malicious?").

Emphasis

The section is explicit that the verdict is not the model's own judgement: it is the platform's
reconciliation of the analyzer data models, the same evaluation the job page badge shows. That
distinction is the whole point of the feature, so it seemed worth stating rather than implying.

It also documents the honest-absence behaviour — no evaluation, or a generic observable, is
reported as such instead of being guessed.

Two things to confirm

1. Version marker. The page uses _Available from version >= X_ markers. I did not add one to
   the new section because the release that will carry #3898 is not decided yet (develop is still
   at 6.7.0). Tell me the target version and I will add it.
2. Screenshots. static/chatbot/quick_actions.png still shows the four old job chips. The text
   is now correct, the image is not. I can regenerate it if you want it in this PR, otherwise it can
   follow when the next release screenshots are refreshed.

[berardifra]

Updated: the quick actions screenshot is refreshed in this PR too, so point 2 of the description is done. Only the version marker question is left.