Twin Emperors: rewrite healer side support and recovery routing

[RovxBot]

Objective

Rewrite Twin Emperors healer-side support so dedicated side healers recover reliably, keep the correct focus targets during swap windows, and stop falling back to raid-healer mode from temporary ownership ambiguity.

Why this exists

The current healer routing is failing before the tank recovery ever stabilizes.

Observed locally:

• tmp/Playerbots.log starts with immediate healer failures:

AQ40 event=movement_failure bot=iledori role=healer ... side=0 reason=outside_leash path=none
AQ40 event=movement_failure bot=paemin role=healer ... side=1 reason=outside_leash path=none
AQ40 event=movement_failure bot=gankuser role=healer ... side=1 reason=outside_leash path=none
AQ40 event=movement_failure bot=kesesha role=healer ... side=0 reason=outside_leash path=none

• Total healer-related routing failures in the run: 27.
• Once healers lose their side anchors, the encounter spirals into pickup failure and split collapse.

Current code hotspots

• src/Ai/Raid/Aq40/Action/RaidAq40Actions_TwinEmperors.cpp
  • Aq40TwinEmperorsHealerSupportAction
  • Aq40TwinEmperorsPrePullStageAction
  • GetTwinRecoveryStepTowardAnchor
  • PrepareTwinRecoveryHold
• src/Ai/Raid/Aq40/Util/RaidAq40Helpers.cpp
  • GetTwinDedicatedTankHealerSide
  • GetTwinHealerFocusTargets
  • IsTwinHealerOutsideSideLeash
  • snapshot ownership checks used by healer fallback
  • kTwinTankHealersPerSide = 2

Required implementation

• Replace the current two-step healer recovery with a proper recovery ladder.
• Minimum routing ladder:
  • direct move to side healer anchor
  • staged step anchor toward side healer anchor
  • center-to-side re-entry anchor when the healer is fully displaced
  • local safe support anchor near the assigned side tank if direct healer anchor occupancy is impossible
• Healer routing must keep retrying within the encounter phase instead of logging path=none and effectively giving up.
• Preserve deterministic healer-side assignment. Do not reshuffle dedicated tank-healers during ordinary swaps.
• Make healer fallback to raid-healer mode stricter:
  • fallback is allowed for explicit Degraded mode
  • fallback is not allowed just because side ownership is temporarily unresolved during an otherwise supported pickup window
• Keep healer focus targets ordered around local tank reality:
  • current owner
  • expected owner
  • reserve owner
• Ensure recovery movement remains compatible with strict Twin movement ownership and does not get overridden by generic movement.

Additional supported-comp contract

The pre-pull and opener contract for healers needs to be explicit for any implementing agent:

• supported Twin runs should start with exactly 2 dedicated tank healers on each side
• those dedicated tank healers should already be staged on their side anchors before pull
• they should not be solved from the center after combat starts unless the encounter has already degraded
• non-dedicated healers should remain central / raid-healer style in pre-pull and opener positioning unless a separate issue explicitly assigns them elsewhere

Reference patterns

• Sunwell / Black Temple position sets show the right style for deterministic support anchors:
  • https://github.com/brighton-chi/mod-playerbots/blob/the-lab/src/Ai/Raid/SunwellPlateau/Action/RaidSunwellEredarTwinsActions.cpp
  • https://github.com/brighton-chi/mod-playerbots/blob/the-lab/src/Ai/Raid/BlackTemple/Util/RaidBlackTempleHelpers.cpp
• PR #2363: ICC V2, Autogear BiS cmd mod-playerbots/mod-playerbots#2363
  • Consistently favors explicit per-encounter positioning over generic formation behavior when movement precision matters.

Validation

• Supported comp test across at least 3 teleports.
• Success criteria:
  • zero movement_failure for Twin healers
  • no path=none healer routing failures
  • side healers remain on their assigned side or re-enter it deterministically
  • healer focus remains on the correct local tank targets during swap recovery
  • each supported opener starts with 2 dedicated tank healers per side already staged correctly
• Degraded-mode test:
  • after a tank death, confirm healer fallback happens only when the encounter explicitly enters Degraded

Related

• Depends on #2 phase and ownership work.
• Coordinate with #6 so spell-driven swap timing can drive healer recovery windows correctly.
• Coordinate with #8 for pre-pull healer staging and opener layout.