[coolestnick]

Closes #339

The labels that screen readers and tooltips use around a thread were full of internal words (run, turn, session, spawned, runtime). I went through the ones listed in the issue and reworded them.

What changed:

• Scroller rail: "Jump to a message" and "Jump to message 4: ..." instead of turn.
• Side pane: the header and loading state say Task now ("Loading task"), the error says "Couldn't load this task.", and the eye button in All threads is "Preview task" instead of "Peek run".
• Spawned gateway children are called "helper agent" now. That word lives in child-labels.ts and is shared by the inline fold, the Agents rail and the group count, so I changed it there once. The fold used to hardcode its own "Open spawned session: ..." link next to that caption; it now builds the link from childKindLabel so the two can't drift apart again.
• Send now: "Stops what the agent is doing now and sends this message right away". The same tooltip also sits in queued-message-pill.tsx, so I updated both. The pill reads "sends after the current reply" now.
• Details rail: the row is "Model" instead of "Runtime", and the tooltip says "The model this task asked for. We are not told which model actually answered."

I left alone the tool verb "Run" for shell commands, the data-run-id / runId identifiers, and the "Loading runs" text on other pages, since they're outside this issue.

Tests that matched the old strings are updated. I also added two small checks: the fold link has to use childKindLabel("spawned_session") and never contain "spawned", and the details rail has to render Model, not Runtime.

Checks:

• cd frontend && bun run test -> 1931 pass, 0 fail
• cd frontend && bun run lint -> no warnings in the changed files
• cd frontend && bun run build -> ok
• bun run typecheck at the root -> ok
• bun test scripts/agent-docs.test.ts -> 5 pass

Before / after

Production build of main next to this branch, same local backend. Native tooltips don't show in screenshots, so those strings are quoted above from the DOM.

Side pane while it loads, opened from All threads:

Before	After

Details rail:

Before	After

Queued message pill:

Before	After

The scroller rail looks the same as before; only its accessible names changed, from "Jump to turn 1: Run the shell command..." to "Jump to message 1: Run the shell command..." on a six-message thread.

[abhishekgahlot2]

Merged, thanks @coolestnick. Screen reader names that make sense to someone who didn't build the product is a real accessibility win.