pets get their action bar, macros arrive, and hunters draw the bow

- a hunter's or warlock's pet has its action bar now: attack, follow, stay, the pet's own spells with cooldowns and autocast sparkles
- the macro system lands: the macro window, the icon chooser, /cast and /macro, and macros dragged onto the action bar
- hunter shots look right at last: the bow draws and releases on the shot, and the arrow lays a spark trail its whole flight
- the options window re-dresses in 1.12's own art with the classic dialog look, and gets a working search box and clickable steppers

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

crates/benilla-protocol/src/messages/update_object/fields/mod.rs

@@ -36,6 +36,12 @@ const FIELD_GAMEOBJECT_LEVEL: u16 = 22;
 /// real client turns an idle unit's body to *face* this target (there is no wire facing for a
 /// stationary re-face — vmangos `SetInFront` is server-only); benilla mirrors that (`face_target`).
 const FIELD_UNIT_TARGET: u16 = 16;
+/// `UNIT_FIELD_SUMMON` (idx 8, `OBJECT_END(6) + 0x2`, a 2-field guid, PUBLIC — VERIFIED vmangos
+/// `UpdateFields_1_12_1.h:42`) — the **inverse** of [`FIELD_UNIT_SUMMONEDBY`] below: the unit this
+/// one has summoned. On our own descriptor it is the pet, and so the anchor of the `"pet"` unit
+/// token; the pet action bar reads its own guid off `SMSG_PET_SPELLS` instead, which is why the
+/// two can legitimately disagree for a beat around a summon (decision 0982).
+const FIELD_UNIT_SUMMON: u16 = 8;
 /// `UNIT_FIELD_SUMMONEDBY` (idx 12, `OBJECT_END(6) + 0x6`, a 2-field guid — vmangos
 /// `UpdateFields_1_12_1.h`) — the summoner of a pet/guardian/totem. With CREATEDBY below, the
 /// combat-text source-ownership classifier's "owned by me" test (wow-re `0x5efea0`).

crates/benilla-protocol/src/messages/update_object/fields/unit.rs

@@ -32,6 +32,12 @@ impl ObjectFields {
     pub fn unit_channel_spell(&self) -> u32 {
         self.get_u32(FIELD_UNIT_CHANNEL_SPELL).unwrap_or(0)
     }
+    /// `UNIT_FIELD_SUMMON` — the guid of the unit this one has summoned, or `None`. On our own
+    /// descriptor that is **our pet**, and so the anchor of the `"pet"` unit token (decision 0982).
+    /// The inverse of [`Self::unit_summoned_by`].
+    pub fn unit_summon(&self) -> Option<u64> {
+        self.get_guid(FIELD_UNIT_SUMMON).filter(|&g| g != 0)
+    }
     /// `UNIT_FIELD_SUMMONEDBY` — the summoner's guid (pet/guardian/totem), or `None` (absent or
     /// explicit 0 — an unowned unit).
     pub fn unit_summoned_by(&self) -> Option<u64> {