The current fixed bottom composer separates node inspection from node editing and competes with graph space. This design records the approved direction to make selected nodes the center of editing, with a contextual toolbar and inline editor that reuse composer behavior instead of duplicating it.
Constraint: Must follow the Minimax Hub display principle requested for node interaction
Rejected: Keep fixed bottom composer as the primary editor | it preserves a global surface that hides graph content and separates action from object
Confidence: high
Scope-risk: narrow
Directive: Extract composer behavior before replacing the UI surface; do not duplicate prompt/model generation logic
Tested: Spec self-review for placeholders and git diff whitespace check
Not-tested: Runtime implementation because this commit is design-only
jiajia