docs: plan reply shorthand and stable output

Assistant: codex
Assistant-Model: gpt-5.6-sol
Assistant-Session: 01a03397-4d51-7fd1-8ff2-946eb22ea2bc

WORK-RECORDS.md

@@ -16,6 +16,7 @@
 | workplan | TAMQ-WP-0005 | finished | — | workplans/TAMQ-WP-0005-terminal-neutral-manual-messaging.md |
 | workplan | TAMQ-WP-0006 | finished | — | workplans/TAMQ-WP-0006-shell-native-message-routing.md |
 | workplan | TAMQ-WP-0007 | finished | — | workplans/TAMQ-WP-0007-terminal-output-notifications.md |
+| workplan | TAMQ-WP-0008 | active | — | workplans/TAMQ-WP-0008-reply-shorthand-stable-output.md |
 | task | TAMQ-WP-ADHOC-2026-08-24-T01 | done | — | workplans/ADHOC-2026-08-24.md |
 | task | TAMQ-WP-0001-T01 | done | — | workplans/TAMQ-WP-0001-statehub-bootstrap.md |
 | task | TAMQ-WP-0001-T02 | done | — | workplans/TAMQ-WP-0001-statehub-bootstrap.md |
@@ -46,3 +47,7 @@
 | task | TAMQ-WP-0007-T03 | done | — | workplans/TAMQ-WP-0007-terminal-output-notifications.md |
 | task | TAMQ-WP-0007-T04 | done | — | workplans/TAMQ-WP-0007-terminal-output-notifications.md |
 | task | TAMQ-WP-0007-T05 | done | — | workplans/TAMQ-WP-0007-terminal-output-notifications.md |
+| task | TAMQ-WP-0008-T01 | progress | — | workplans/TAMQ-WP-0008-reply-shorthand-stable-output.md |
+| task | TAMQ-WP-0008-T02 | todo | — | workplans/TAMQ-WP-0008-reply-shorthand-stable-output.md |
+| task | TAMQ-WP-0008-T03 | todo | — | workplans/TAMQ-WP-0008-reply-shorthand-stable-output.md |
+| task | TAMQ-WP-0008-T04 | todo | — | workplans/TAMQ-WP-0008-reply-shorthand-stable-output.md |

workplans/TAMQ-WP-0008-reply-shorthand-stable-output.md

@@ -0,0 +1,92 @@
+---
+id: TAMQ-WP-0008
+type: workplan
+title: "Counterparty reply shorthand and stable terminal output"
+domain: communication
+repo: tmux-amq
+status: active
+owner: codex
+topic_slug: coulomb-social
+planning_priority: P0
+planning_order: 13
+created: "2026-08-24"
+updated: "2026-08-24"
+---
+
+# Counterparty reply shorthand and stable terminal output
+
+Add a conversation-oriented reply convention and keep asynchronous message
+output above the current input row instead of visually breaking the prompt.
+
+## Required operator contract
+
+If `audit-core` most recently received a message from `flex-auth`, this sends a
+reply to `flex-auth`:
+
+```bash
+@ Thanks, I will take a look.
+```
+
+The generic `@` command resolves the latest durable inbound message for the
+current `TAMQ_REPO`, regardless of acknowledgement state. It excludes
+self-addressed messages. If there is no counterparty, it fails visibly and
+queues nothing.
+
+When a message arrives, tamq uses tmux's current pane cursor position and
+VT100-compatible scroll margins to scroll only the rows above the input cursor,
+write the comment immediately above it, restore the full scroll region, and
+restore the cursor. The current input row and cursor position remain stable.
+
+## Add durable latest-counterparty resolution
+
+```task
+id: TAMQ-WP-0008-T01
+status: progress
+priority: high
+```
+
+Query the latest inbound message by creation order for the current repository,
+excluding self-addressed rows. Add `tamq reply MESSAGE...` and a tamq-owned
+generic `@` executable alongside the repository-specific shims. Preserve
+argument boundaries, require `TAMQ_REPO`, reuse target validation and send
+transport, and refuse collision with an unrelated existing `@` command.
+
+## Keep input position stable during output
+
+```task
+id: TAMQ-WP-0008-T02
+status: todo
+priority: high
+```
+
+Resolve `cursor_y`, `pane_height`, and the pane PTY atomically through tmux.
+For a cursor with rows above it, generate a bounded DECSTBM scroll-region frame
+that saves/restores the cursor and resets the full scrolling region. Sanitize
+message content before framing and retain the simple output fallback when no
+row exists above the cursor. Never emit input bytes.
+
+## Prove conversation and screen behavior
+
+```task
+id: TAMQ-WP-0008-T03
+status: todo
+priority: high
+```
+
+Test latest inbound selection across pending/acknowledged and self-addressed
+messages, missing identity/counterparty errors, generic shim arguments and
+ownership collision, cursor-aware frames, and real tmux behavior with a partial
+input line. Prove the input text and cursor coordinates are unchanged while the
+message becomes visible immediately above them.
+
+## Install and document the interaction convention
+
+```task
+id: TAMQ-WP-0008-T04
+status: todo
+priority: high
+```
+
+Update help, README, and SCOPE; run complete checks; install the build; exercise
+`@ MESSAGE` in both directions in a live two-window session; and retain only
+user messages pending after acknowledging controlled smoke records.