[xvcezrqpbxtpzblrt]

Depends on #4435 for its two routes (GET /api/chat/subagents/:childId, POST /api/chat/subagent/prompt) and for the send outcome in store.ts: those live in files that PR also changes. Without it this branch's panel has nothing to call. Review #4435 first.

Problem

• A helper row was one line of text. There was no way to read what the helper actually said, and no way to answer it.
• A helper that had been stopped said "can continue" and then there was nothing to continue it with.
• When a send was refused, the draft and the quotes had already been cleared.

Result

• Clicking a helper row opens its conversation, refreshed while it runs, bounded (200 entries / 64 K characters per helper, 100 helpers).
• A box sends a message to the helper; interrupted rows also get Continue, in the person's language.
• Sends report an outcome; only an accepted send clears the draft and quotes, and a refusal restores them once, in the session they came from.
• The run bar shows how many helpers work, with one stop for all.

Validation

node --test tests/agent-subagent-transcript.test.mjs tests/agent-subagent-chat.test.mjs tests/chat-send-draft.test.mjs tests/agent-children.test.mjs → 39 pass, 0 fail (the last one needs STRATA_HARNESS_DIR for the real-Harness cases).

Limits

• After a host restart a helper needs one ordinary chat message before it accepts one; the panel says so.
• A helper continued outside a chat turn cannot be stopped from its row.
• No browser run: the click path is covered by source assertions and store tests.

[xvcezrqpbxtpzblrt]

Superseded by #4606, which carries this change with the rest of the 0.2.7 branch. Closing so the review has one place.