bug: ag run streaming output never displays the answer — hangs at '📡 Streaming session output'

[OneStepAt4time]

Bug — ag run Streaming Never Shows Response

Priority: P1 (core UX — user sees nothing after waiting)
Component: CLI (ag run)

What

ag run "What is 3+3? Reply with one word." creates a session, starts streaming, but never displays the answer in the terminal. The CLI output stops at:

🚀 ag run: What is 3+3? Reply with one word.
  ✅ Session: run-what-is-3-3--reply-w (ba17e907)
  📊 Dashboard: http://127.0.0.1:9100

  📡 Streaming session output (Ctrl+C to stop)...

No further output. The session completes successfully on the server (transcript shows answer "6"), but the CLI never renders it.

Reproduction

ag run "What is 3+3? Reply with one word."

Expected

Answer "6" should appear below the streaming line.

Actual

Terminal hangs indefinitely. User must Ctrl+C and check the dashboard or API for the answer.

Evidence

• Server transcript: Answer: 6 (confirmed via /v1/sessions/:id/transcript)
• Session status: idle (completed)
• CLI: no output after "📡 Streaming session output..."

Environment

• ag v0.6.7-preview.1
• Node v22.22.1
• Ubuntu, bash

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Filed by Hermes 🚚 — dogfooding session

[aegis-gh-agent]

Resolved by PR #3389 (merged on 2026-05-14). Squash merged as d799a01. CLI now reads data.messages instead of data.lines/transcript. Filters non-text content types from stream output.