[bartbunting]

Codex can send command output through _meta.terminal_output_delta.data. Agent Shell currently reads content blocks and rawOutput.formatted_output, so command blocks show the command without its output.

This change accumulates output chunks per tool call and uses the retained output for rendering and transcripts. Status-only updates preserve that output, while complete content or raw-output snapshots replace it. Existing end-of-turn cleanup releases the accumulated state.

Tests cover interleaved commands, output delivered at completion, snapshot replacement, expansion and navigation, restored history, and cleanup.

Validation:
• Tests pass against source and with compiled code.
• No new warnings appear after checkdoc and byte compilation.
• Indentation and whitespace checks pass.
• Tested with Emacs 31.0.90.

Checklist

• I agree to communicate (PR description and comments) with the author myself (not AI-generated).
• I've reviewed all code in PR myself and will vouch for its quality.
• I've read and followed the Contributing guidelines.
• I've filed a feature request/discussion for a new feature.
• I'm making visual changes, so I'm including screenshots so you can view and discuss.
• I've added tests where applicable.
• I've updated documentation where necessary.
• I've run M-x checkdoc and M-x byte-compile-file.