[gmatossian]

The Messaging parent opened with a long text stack and a combined diagram that the owner found hard to read. Implements the owner-selected C layout: three short queue, pub/sub, and retained-stream sketches, each followed by concise Markdown use/caveat bullets.

Removes the old combined graphic and moves the key distinctions beside the matching model. Keeps the database-jobs note, brief terminology, existing identity and children, and Draft editorial status. No renderer or child-topic changes.

Follow-up to #113; owner selected C after reviewing three concrete mockups. AI-assisted implementation, responsive review, and deliberate final-diff review completed by Codex; no independent review selected. No blocking findings. Existing delegation authorizes merge once ready and Actions pass.

Validation:

• npm run check passed: 57 app tests, 119 tooling tests, 38 browser tests, formatting, lint, generation, type checking, and build.
• Reviewed at 390px and 1280px; all three images load, labels readable, no page overflow.
• git diff --cached --check passed; only parent Markdown and local SVG assets changed.
• Existing non-failing bundle warning: 630.57 kB against 500 kB warning budget.