Why: Codex stop-time review #3 flagged "Type 0 component handling is
incomplete". The earlier C1 fix (orchestrator-plan-classify helper +
isMobileFullScreen heuristic) covered the orchestrator path, but four
more places still bucketed narrow widths (≤480 / ≤500) as mobile and
mishandled component-shaped plans.
What:
- agent-tool-executor.ts: replace `width<=500 ? 375 : 1200` bucket on
setGenerationCanvasWidth with the inserted node's actual width — a
400-wide profile card now estimates text against 400, not 375.
- design-type-presets.ts: add 'component' to DesignType union with
width=400, height=0, and a single-section default. detectDesignType
matches "X card / X badge / X chip / ..." prompts BEFORE the mobile
/ dashboard check, so the parse-failure fallback returns a 400px
component instead of a 1200px landing-page for "design a profile
card". Disqualified when prompt also names a screen / page.
- orchestrator-prompt-optimizer.ts: 3 spots — platform selection now
uses preset.type==='mobile-screen' (component groups with webapp,
not mobile, since it has no status bar / bottom nav); compact
prompt rules and subtask hint get a component branch ("Use width=400
height=0, exactly 1 subtask, no chrome"); fallback height map gives
components a single 200px region instead of 800.
- orchestrator-planning.ts: buildFallbackHeights treats narrow +
auto-height plans as component-shape and emits 200px sections,
preventing the prior "812 / 1 = 812-tall card" output.
2 new tests pin: (a) "design a clean profile card" → 400×0 single
"Component" subtask with 200px region; (b) "design a card screen page"
must NOT shortcut to component (screen/page disqualifier holds).