Feature/sailing helm

[MouldyToast]

Sailing Engine -- World-Entity Framework + Helm Navigation

Adds the core sailing engine: world-entity boat spawning, boarding/disembarking, per-tick kinematics, 16-way helm steering, and deck furnishing. The full sail loop works end-to-end against the real client.

What works

Board at a dock -> Navigate the helm -> first ocean click departs straight ahead at full throttle -> 16-way steering by clicking -> Stop-navigating -> decelerate -> Disembark.

World-Entity Engine (Phases 0-2c)

• Dynamic instance regions allocated per boat, zone-copied from static template maps
• WORLDENTITY_INFO protocol: world-entity avatar lifecycle, coord updates, angle broadcasts
• Player ride/unride onto world entities with worldentity_ride bypass (root rebuild + map_loader.load_area())
• Zone-update fixes: aboard root zone view centering, world-scoped deck zone updates, zone-state replay on high-res view entry

Sailing Module (Phase 3)

• Docks & Gangplank -- Bidirectional board/disembark at Port Sarim (and extensible to other docks). Player faces south on board to match the capture's departure orientation
• BoatKinematics -- Per-tick speed ramp (+/- acceleration), shortest-path turning (+/- 128 angle units/tick), movement integration along post-turn angle, q32 fixed-point quantization. Parity-tested: 0 mismatches vs reference across 2048 angles x 7 speeds and 2000 random 40-tick trajectories
• Helm + SET_HEADING -- All 42 steering multiloc variants bound (Navigate / Stop-navigating), SetHeadingHandler net handler -> SailingEvent.SetHeading -> content, interaction-mode switching (heading tile-mode while steering, walk tile-mode on release), helmsman tracking with releaseHelm safety net on every off-boat path
• Deck Furnishing -- 43 facility locs (12 raft / 14 skiff / 17 sloop) spawned per boat type via LocRepository onto the instance region. Helm, sails, cargo, keel, trim, and ambience emitters all server-spawned (the static template zones carry only the hull shell -- this is how per-boat customisation works)
• Three boat types -- Raft, Skiff, Sloop with distinct speed/acceleration profiles, helm anim/synth sets, and deck furniture layouts

New Files

File	Purpose
BoatKinematics.kt	Singleton integrator -- speed ramp, turn, movement
BoatKinematicsScript.kt	LateCycle tick binding
HelmEvents.kt	Navigate/Stop/steer, 42 loc bindings, SetHeading consumer
SailingMoveModes.kt	STOPPED/HALF/FULL/REVERSE/HELM_IDLE constants
DeckLoc.kt / DeckLocs.kt	Per-type facility furniture data
InteractionModes.kt	SetInteractionMode/ResetInteractionMode output wrappers
SailingEvent.kt	SetHeading(player, heading) UnboundEvent
SetHeadingHandler.kt	Net handler for SET_HEADING, gates heading > 15

Modified Files

Boat.kt, BoatType.kt, BoatManager.kt, SailingVars.kt, GangplankEvents.kt, SailingDebugCommands.kt, MessageConsumerProvider.kt

Known Gaps / Next Steps

• Sail state machine -- down/half/full transitions with loc anim pairs + synths. Blocked on op-mask support (sails need restricted ops per state)
• Helm keepalive anims -- 10-tick resend of player loop anim + helm loc loop anim while navigating (player currently stands still at helm after grab)
• Sidepanel UI -- IF 937 (speed controls, navigator name, move-mode display)
• Boat-selection UI -- IF 934 modal for choosing which boat to take out on boarding (currently spawns a default raft)
• OpWorldEntity handlers -- rsprot decoders exist, OpenRune has none yet
• Boarding choreography -- Fade transitions, synth 10754, music region changes
• Boat ownership -- Ownership varbits (Pandemonium quest gate)
• Facility customisation -- IF 939 modal for upgrade tiers (C4 blocked on build-confirm capture)
• Mooring points -- Loc 59867-59893 coords at other docks unverified
• Logout/login aboard -- Not safe to log out aboard; heading tile-mode would persist incorrectly (lockedin self-heal covers the varbit half)
• No root-world collision for boats -- Boats clip through land
• Moored boats never despawn -- One raft per visited dock until ::delboat or restart

Debug Commands

• ::setheading <0-2047> -- Set boat angle directly
• ::setspeed <value> -- Set boat speed directly
• ::moveboat <dx> <dz> -- Teleport boat (syncs targetAngle)
• ::exitboat -- Force-disembark with helm release
• ::delboat -- Remove a moored boat