[M2][PR2.5] Clarify that best take is not perfect

[kymuco]

Goal

Clarify musician-facing wording so users understand that the best take means best among submitted takes, not objectively perfect.

Scope

Markdown/report wording only.

Do not change:

• scoring;
• ranking;
• batch selection;
• session summary data;
• JSON payload contracts;
• CLI/API behavior.

Add

Improve wording around best-take sections, for example:

Best take means strongest among the submitted takes, not a perfect performance.

Use this idea in relevant session/batch artifacts where best-take decisions are shown.

Acceptance

• Best-take wording is explicit and not overconfident.
• The wording appears near the best-take/session decision area.
• Existing Why this take won wording remains useful.
• Tests cover the new phrase or equivalent wording.
• No ranking or scoring behavior changes.