Modify-card Tier-1 state badge frozen at build time — PARTIAL FAILURE shows APPLIED on PO/SO morph path

[dougborg]

Problem

The Tier-1 state badge on _render_preview_header is rendered from a Python-time string (applied_state_label / applied_state_variant) which is baked into the Prefab tree at build time. On the in-place preview→Confirm morph path, the header badge ALWAYS reads APPLIED (default/green variant) — even when the apply outcome is PARTIAL FAILURE or FAILED.

The on_success SetState chain in build_so_modify_ui (and similarly in build_po_modify_ui) already seeds state.applied_outcome_label / state.applied_outcome_variant slots, but nothing binds them to the header Badge. The per-field ✗ glyphs and the state-driven sub-entity failed-action Alert provide partial signals, but the prominent Tier-1 badge stays frozen at success chrome.

The standalone-applied path (when the apply response is rendered directly, is_preview=False) already handles this correctly — applied_state_label / applied_state_variant are overwritten with the actual outcome bucket before tree construction. The gap is specifically the in-place morph path.

Where this manifests

• SO modify card (design(mcp): build_so_modify_ui — diff-decorated SO modify card (#721 child) #723 / feat(mcp): build_so_modify_ui — diff-decorated SO modify card #858): preview → Confirm → partial failure → header badge says APPLIED while the sub-entity Alert says "1 sub-entity failure(s)".
• PO modify card (design(mcp): build_po_modify_ui — diff-decorated PO modify card (#721 child) #722 / feat(mcp): per-entity PO modify card with field-level diff overlay — #722 #755): same shape, same gap. Caught by the same reviewer on both.
• BOM modify card (design(mcp): build_bom_modify_ui — per-row content (ingredient × qty) for manage_product_bom preview/apply (#721 child) #811) — already solved here, uses parallel Badge branches gated on If(Rx("applied_outcome_label") == "PARTIAL FAILURE"). The fix pattern is established.

Fix shape

Convert _render_preview_header to emit two parallel Badge branches keyed off state.applied_outcome_label, mirroring the BOM card. Cleanest factoring is probably a helper that takes the state-slot names and renders the If/Elif/Else fork once.

Because the rendered tree shape changes for every consumer of _render_preview_header, this is a cross-card sweep, not a single-card fix. Splitting it into its own PR keeps #858 + #722 reviewable as the per-card landing for SO/PO and lets the badge-morph land as one focused diff.

Acceptance criteria

• Existing PO + SO modify card tests still pass.
• Browser test for the SO morph path (added in feat(mcp): build_so_modify_ui — diff-decorated SO modify card #858) extends to assert the post-Confirm header badge reads PARTIAL FAILURE / destructive.
• BOM modify card pattern factored into a reusable header helper, or the SO/PO header builders adopt the same inline If/Elif/Else.

Refs

• Caught by code-reviewer on feat(mcp): build_so_modify_ui — diff-decorated SO modify card #858 (this PR — see SUGGESTION [Feature]: Update Documentation and make sure pydocs are generated and published #3 of the SO modify card review).
• Pre-existing on design(mcp): build_po_modify_ui — diff-decorated PO modify card (#721 child) #722 — same caller pattern, same gap.
• BOM modify (design(mcp): build_bom_modify_ui — per-row content (ingredient × qty) for manage_product_bom preview/apply (#721 child) #811) already solved it; the morphing Badge pattern is the precedent to follow.

Priority + Workstream

P2-soon (visible UX bug but not a workflow break — the sub-entity Alert + per-action ✗ glyphs still surface the failure), Cards workstream.