the action bars' empty slots go ghost, and a rooted creature stays put

- picking a spell up off the bar no longer blacks out every empty slot: `UI-Quickslot` is a FILLED 60%-black plate, not a hollow ring (decoded off the shipped BLPs — Quickslot2's interior is RGBA 0,0,0,0, Quickslot's 0,0,0,153), and the reference dims it to half alpha in `ActionButton_ShowGrid`, so an empty well now ghosts at 30% black where it read as a hole; the wow-re cross-check then found the reference never UN-dims it (a 3-argument `SetVertexColor` preserves the current alpha at `0x79abd0`, and `SetNormalTexture` reuses the region), so in the real client the first drag leaves every button's border at half alpha for the rest of the session — benilla ends the dim on purpose and records it as the divergence it is (1782)
- the bag bar is the reference's own `MainMenuBarBagButtons.xml` (window 3 of the stock-first migration), and the swap found a real bug rather than a move: the reference's `ItemAnim_OnEvent` matches a push against the button's inventory-slot id (20..23) and benilla emitted its own container numbering (1..4), so all four bag-push cards would have silently never played against the stock body — `push_container` now emits the reference's selector (`bag + 1`), which is what an addon expects anyway; beside it, a readiness probe that asks the LOADER, not a grep, which of the 85 stock windows load off the player's chain today (58 do; the 27 that don't name their own blocker)
- a rooted, hovering, water-walking or walking creature reached benilla as an unhandled opcode: the twelve `SMSG_SPLINE_MOVE_*` (the observer twin of the ack'd force family — bare packed guid, no ack, any unit) now decode into one MOVEMENTFLAGS word per unit, which benilla kept for our mover and for a relayed player and not at all for a creature, the one body this family is ever addressed to; ROOT wipes the direction bits so the dead-reckon stops walking a rooted body on for its next heartbeat (`0x7c7340`), HOVER clears a yard off the floor without climbing a body already inside that yard (`0x636e81`), WATERWALK elects the liquid surface against the terrain, SAFE_FALL's terminal is 7.0 not 60.148 (`0x7c5d23`), and SET_RUN_MODE's bool is inverted against the bit, folded at the parse; the inspect card names a unit's granted modes in words (`granted rooted+hover`) so a creature resting a yard off the floor reads as intended rather than broken

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

crates/benilla-protocol/src/messages/parse.rs

@@ -16,6 +16,7 @@ use super::{
     mirror_timer, monster_move, movement, opcode, page_text, pet, petition, progression, pvp,
     quest, social, spellbook, spells, stable, summon, taxi, trade, trainer, update_object, vendor,
     world_state, Character, CreatureQueryInfo, JumpInfo, MoveMode, ServerPacket, SpeedKind,
+    SplineMode,
 };
 
 /// Read one `SMSG_FORCE_*_SPEED_CHANGE` body — `[packed mover guid][u32 counter][f32 speed]`,
@@ -891,6 +892,45 @@ pub fn parse_server(opcode: u16, body: &[u8]) -> io::Result<ServerPacket> {
                 apply,
             }
         }
+        // **The observer movement-mode family** (decision 1780) — the spline-move twelve. Body is a
+        // BARE packed guid: no counter, no `MovementInfo`, and nothing to ack (VERIFIED vmangos
+        // `MovementPacketSender::SendMovementFlagChangeToAll`/`SendToggleRunWalkToAll`, and the
+        // reference's single handler `0x603c80`, which reads one packed guid and dispatches).
+        // `guid` is any unit, not our mover — the constants block in `opcode` carries the arm map.
+        opcode::SMSG_SPLINE_MOVE_ROOT
+        | opcode::SMSG_SPLINE_MOVE_UNROOT
+        | opcode::SMSG_SPLINE_MOVE_WATER_WALK
+        | opcode::SMSG_SPLINE_MOVE_LAND_WALK
+        | opcode::SMSG_SPLINE_MOVE_FEATHER_FALL
+        | opcode::SMSG_SPLINE_MOVE_NORMAL_FALL
+        | opcode::SMSG_SPLINE_MOVE_SET_HOVER
+        | opcode::SMSG_SPLINE_MOVE_UNSET_HOVER
+        | opcode::SMSG_SPLINE_MOVE_START_SWIM
+        | opcode::SMSG_SPLINE_MOVE_STOP_SWIM
+        | opcode::SMSG_SPLINE_MOVE_SET_RUN_MODE
+        | opcode::SMSG_SPLINE_MOVE_SET_WALK_MODE => {
+            let (mode, apply) = match opcode {
+                opcode::SMSG_SPLINE_MOVE_ROOT => (SplineMode::Root, true),
+                opcode::SMSG_SPLINE_MOVE_UNROOT => (SplineMode::Root, false),
+                opcode::SMSG_SPLINE_MOVE_WATER_WALK => (SplineMode::WaterWalk, true),
+                opcode::SMSG_SPLINE_MOVE_LAND_WALK => (SplineMode::WaterWalk, false),
+                opcode::SMSG_SPLINE_MOVE_FEATHER_FALL => (SplineMode::FeatherFall, true),
+                opcode::SMSG_SPLINE_MOVE_NORMAL_FALL => (SplineMode::FeatherFall, false),
+                opcode::SMSG_SPLINE_MOVE_SET_HOVER => (SplineMode::Hover, true),
+                opcode::SMSG_SPLINE_MOVE_UNSET_HOVER => (SplineMode::Hover, false),
+                opcode::SMSG_SPLINE_MOVE_START_SWIM => (SplineMode::Swimming, true),
+                opcode::SMSG_SPLINE_MOVE_STOP_SWIM => (SplineMode::Swimming, false),
+                // The one inverted pair: RUN_MODE *clears* `MOVEFLAG_WALK_MODE`, because the
+                // reference's `0x617e80` feeds the opcode's bool to `SetRunMode 0x7c71c0`.
+                opcode::SMSG_SPLINE_MOVE_SET_WALK_MODE => (SplineMode::WalkMode, true),
+                _ => (SplineMode::WalkMode, false),
+            };
+            ServerPacket::SplineMoveMode {
+                guid: read_packed_guid(&mut r)?,
+                mode,
+                apply,
+            }
+        }
         // **The knockback the server aims at our mover** (decision 1702): `packed guid + u32
         // counter`, then the launch quad `vcos, vsin, speedXY, speedZ` (VERIFIED vmangos
         // `MovementPacketSender.cpp:261-277`, the `> CLIENT_BUILD_1_9_4` branch). The quad reads