Ensure all destructive/state-changing commands require --yes confirmation

[scottlovegrove]

Problem

Currently only tw thread delete requires the --yes flag before executing. All other destructive and state-changing commands execute immediately without confirmation.

Commands that execute without --yes today:

Deletes (irreversible):

• tw msg delete — permanently deletes a conversation message
• tw comment delete — permanently deletes a thread comment

Archive/state changes:

• tw thread done — archives a thread
• tw conversation done — archives a conversation

Why this matters

From the 7 Principles for Agent-Friendly CLIs, Principle 4 (Safe Retries and Explicit Mutation Boundaries):

Agents retry, resume, and replay commands more frequently than humans. Dangerous mutations require explicit flags.

Agents operating in retry loops won't notice if a delete ran twice — and for archive operations, because they're idempotent (archiving an already-archived item is a no-op), an agent won't get an error signal that it already ran. The --yes flag acts as an explicit acknowledgement that the agent intended the mutation.

The existing thread delete implementation is the reference pattern:

• Without --yes: shows what would happen and exits (non-destructive preview)
• With --json but without --yes: errors with "--yes is required to execute deletion in --json mode"
• With --yes: executes the operation

Scope

All of the following should follow the thread delete pattern:

Command	Type	Currently requires --yes
tw thread delete	Delete	✅ Yes
tw msg delete	Delete	❌ No
tw comment delete	Delete	❌ No
tw thread done	Archive	❌ No
tw conversation done	Archive	❌ No

[scottlovegrove]

This aligns with Principle 4 (Safe Retries and Explicit Mutation Boundaries) from the 7 Principles for Agent-Friendly CLIs analysis:

Agents retry, resume, and replay commands more frequently than humans. Dangerous mutations require explicit flags.

The --yes pattern is exactly what the article recommends — and the existing thread delete implementation is already the gold standard here (requiring --yes, refusing to prompt in --json mode, supporting --dry-run). Just need to ensure all other delete commands match it.