[kongesque]

Group text, mentions, and replies could fail with TalkException 82 because the CLI discarded the negotiated group encryption version and always sent a V2 envelope. Sends now select V1/V2 from the latest group-key response and label the envelope consistently. Unsupported versions fail before sending, and V2 encryption failures no longer fall back to mislabeled V1 chunks.

Adds safe numeric request diagnostics and an opt-in messages --diagnostics --json view of returned IDs before decryption. This branch also fixes chat search when a contact profile is unavailable. Protocol provenance, diagnostic contracts, and regression coverage are documented.

Validation:

• Build and CLI help smoke check passed.
• Main contributor race suite, goimports, go vet, and staticcheck passed.
• Authorized live baseline, mention, and reply sends each succeeded once in the designated two-member test group. All three decrypted in history; mention target and reply relationship matched. No automatic mutation retries or group-key registration occurred.

The original issue's historical reply remains unexplained. Attachment and V2 flows have synthetic coverage; live verification covered negotiated V1 text, mention, and reply sends.

Closes #20.