Clear the inline diff review automatically after a successful send

[h0x91b]

Feedback from Alexander Kiselyov: the review cycle was always four steps — write comments, "Send to Agent", "Reset review", confirm a destructive dialog. After a successful send the comments are already delivered, so the reset and its confirmation were pure friction.

• A successful send now clears the inline review comments (and their persisted entry) automatically — no extra click, no confirmation dialog.
• A failed send changes nothing: the comments survive so the reviewer can retry.
• The manual "Reset review" button keeps its confirmation for the "changed my mind, drop the comments without sending" case.
• The success toast now says the review was sent and cleared, so the disappearance is not a surprise (en/ru/es).