[dialogue][major] Parley header shows the PLAYER not the NPC; Parley NPC can switch mid-interaction

[100yenadmin]

From rc1+rc2 persona evidence (veteran/adversarial). The Parley pane header identifies the player character instead of the NPC being spoken TO; clicking a second skill mid-parley can switch the target NPC. The #741 sticky-campaign fix removed one switching ROOT (cross-campaign); this issue tracks the remaining in-campaign dialogue-target binding. Verify post-#741 at the next sweep, then fix the header + target stickiness.

[100yenadmin]

Engine-audit deep spec (SYN-07 / F10-2) — engine anchor for the Parley-NPC instability

What is broken

The engine half behind "Parley NPC can switch mid-interaction": generate_parley_options has no NPC binding at all — it accepts no npc_id, ignores the target's attitude for DC (hostile −80 and helpful +80 yield the same menu), and its situation parameter is dead (zero body references) while every real call ships 40–100 words into it.

Why (root cause, file:line)

• servers/engine/server.py:6636-6731 re-read on main: no npc_id param; the body reads only actor/difficulty/house_rules/event_id. _suggested_dc (:6627-6632) is a function of two strings — attitude never consulted.
• situation: str = "" sits in the signature with zero body references (confirmed dead). Transcript evidence: 48 calls carrying ≥20-char situation prose, 8 distinct shapes, all rich — DM output tokens burned into a schema lie.
• Attitude data is load-bearing elsewhere (endings/*.json gates) — the gauge exists and is queryable; this tool just never reads it.
• Severity note (P2, corrected from P1): the documented contract is explicitly actor-centric ("suggested_dc comes from a fixed band keyed off difficulty") and the DM has attitude_value in scene_context — so this is a design gap + one genuine small defect (the dead param), not a broken contract. It is, however, the engine-side anchor this issue's header/NPC-switch fix should bind to.

How to fix (the spec — payload ready)

• Additive npc_id="" (+ id aliases); response gains npc: {id, name, attitude_band, attitude_value, met}.
• Attitude-derived default difficulty as a band shift (explicit non-default difficulty wins); unknown id degrades gracefully like event_id does.
• Echo situation back in the payload (makes the param real instead of deleting it from the frozen wire).
• npc_id absent → byte-identical payload (frozen-wire-safe). Read-only stays read-only; tool still never rolls (engine-rolls invariant unaffected).
• Viewer side: once the payload carries npc.{id,name}, the Parley header should render THAT NPC and pin it for the interaction — fixing both halves of this issue against an authoritative binding instead of inference.

Test strategy

• hostile/−60 NPC, default difficulty → hard band; explicit difficulty overrides; npc_id absent → today's payload byte-identical; npc.id + met carried through.

Scorecard impact

story_craft + cross_persona_sat (mid-parley identity stability).

—
effort: M · confidence: high · finding-ids: SYN-07, F10-2 · related: #319 (difficulty context label can consume the same payload), #640 (facade-side selector half)
Source: docs/audits/ENGINE-AUDIT-2026-06-11.md (PR #768), synthesis SYN-07 + unit 10.

[100yenadmin]

Fixed + merged in #923 (parley header now pins the NPC; disposition meter on the Dialogue screen). fast_gate PASS on main f0dcc7d.