FM pane information design: mailbox, memories and catch-up as designed views

Context

Operator critique 2026-08-16, verbatim intent: "Mailbox view design? memories and summaries design and ux?" — the drawer panes render CORRECT data as undesigned lists. The §04 arc (#17263 spec + #17264/#17265 chrome passes) covers the cockpit's shared visual language; this ticket covers what those deliberately leave out: the CONTENT-level information design of the three list-bearing panes.

The Problem

OperatorMailbox, MemoriesPane, and CatchUpPane were built data-truth-first (bounded stores, honest degradation, frame-free roots per the drawer-shell contract) — and their content rendering stayed at "rows of text": no designed message anatomy (sender/subject/age/read-state hierarchy), no threading affordance in the mailbox, memories as undifferentiated entries with no scan pattern (kind, recency, session grouping), catch-up partitions without visual weight. A pane whose data pipeline is rigorous but whose surface reads like debug output is precisely the "love missing" class — the truth deserves typography.

The Fix

Design-first, then implement, per pane against #17263's ladders:

1. Mailbox: message-row anatomy (sender identity mark, subject weight, relative age, read/unread state, priority), thread grouping, compose affordance placement — the operator's steering surface should read like a mail client, not a log.
2. Memories: entry cards with kind/recency scan pattern, session grouping, the retrieval-hint affordance — a memory browser, not a dump.
3. Catch-up: partition hierarchy with visual weight (what happened since you looked — the headline pane), source-slot freshness as designed metadata rather than appended text.

Store contracts, derivations, and the drawer-shell frame ownership stay untouched — this is view-layer information design over the existing data planes.

Acceptance Criteria

• Each pane has a design sketch (§04-consistent) reviewed BEFORE its implementation lands — the spec-first gate, per-pane.
• Mailbox rows carry the designed anatomy incl. read-state and priority; threads group visually.
• Memories render with the kind/recency scan pattern; a cold pane and a full pane both read intentionally.
• Catch-up partitions carry designed hierarchy; freshness renders as metadata, not suffix text.
• Shell-seam guard stays green (pane roots stay frame-free); zero CSS-in-JS; both themes via tokens.

Out of Scope

The shared chrome ladders (#17263/#17264/#17265) · the shell navigation vocabulary (sibling ticket, same day) · new data capabilities (real-data wiring is its own ticket) · AgentDetail/WakeRoute panes (follow-up if this pattern proves out — deliberately narrow first cut).

Related

Epic #14560 (parent) · #17263 (the bar) · #17219 (the drawer-shell frame contract these panes render inside) · the real-data sibling (filed same day).

Live latest-open sweep: latest 10 re-checked 2026-08-16T22:30Z (fresh after the #17263–#17266 batch), no equivalent; A2A herd window clean.

Origin Session ID: 71baabc5-3ebe-46ff-99ce-a301e78cb7c5

Retrieval Hint: query_raw_memories("FM pane information design mailbox memories catch-up designed views")