fix(spell): never auto-unshift out of Spirit of Redemption

3.3.5's and 4.4.2's SpellShapeshiftForm.dbc give Spirit of Redemption
(form 32) flags 0x4100, which include SHAPESHIFT_FORM_FLAG_NO_AUTO_UNSHIFT
(0x100). So the later clients' CGUnit_C::CanAutoUnshift refuses it, and no
cast, interaction or item use cancels it. 1.12's row has flags 0, so with
autoUnshift on, our CanAutoUnshift allowed it. A priest in Spirit of
Redemption who cast a NOT_SHAPESHIFT spell, right-clicked an NPC or object,
used an item or opened the flight map sent CMSG_CANCEL_AURA for it.

The later-client flags that 1.12's rows lack now sit in one table:
CAN_INTERACT on the druid forms and Ghost Wolf (read only while
autoUnshift is on, as before), and NO_AUTO_UNSHIFT on form 32, which
CanAutoUnshift reads unconditionally, as 4.3.4 does. With it, every
autoUnshift site leaves Spirit of Redemption on and keeps 1.12's own
refusal.

The comment on FormCanInteract also records why a locked object still
unshifts. It opens by a spell (Opening 6478 for chests and barrels), and
the server's CheckCast form test refuses that spell on 1.12's spell data,
which keeps SPELL_ATTR_NOT_SHAPESHIFT (3.3.5 dropped it).

docs/API.md

@@ -22579,7 +22579,8 @@ the usual error.
 Each action occurs only when nothing else blocks the cast. For example, if the
 spell needs a target and you have none, you stay mounted. If the spell shows
 the targeting cursor, the action occurs when you select the target. `autoDismount`
-and `autoUnshift` do nothing on a flight path.
+and `autoUnshift` do nothing on a flight path. `autoUnshift` never removes
+Spirit of Redemption.
 
 When `autoUnshift` is `1`, an action button stays usable in a form that the
 cast can leave. For example, Healing Touch in Bear Form and Renew in

src/Offsets.h

@@ -12071,7 +12071,8 @@ enum Offsets {
     // column 11: the parsed 1.12 DBC gives 0x7 for the warrior stances, 0x1
     // Stealth, 0x9 Shadowform, matching 3.3.5's column. 0x100 is the form
     // flag 3.3.5 / 4.3.4 `CGUnit_C::CanAutoUnshift` refuses on (set there
-    // only on Spirit of Redemption and the Ghoul forms); no 1.12 row has it.
+    // only on Spirit of Redemption and the Ghoul forms); no 1.12 row has it,
+    // so Spell::AutoPrepare adds it to Spirit of Redemption (form 32).
     VAR_SPELL_SHAPESHIFT_FORM_RECORDS = 0x00C0D774,
     VAR_SPELL_SHAPESHIFT_FORM_COUNT = 0x00C0D778,
     OFF_SPELL_SHAPESHIFT_FORM_FLAGS = 0x2C,

src/spell/AutoPrepare.cpp

@@ -45,7 +45,8 @@
 //     so 4.3.4 talks and uses objects in them without leaving the form.
 //     1.12's rows lack it; with autoUnshift on, the gates read it as the
 //     later clients give it, so the cancels below are only for a form that
-//     cannot interact in either client.
+//     cannot interact in either client. Spirit of Redemption likewise
+//     reads the later clients' NO_AUTO_UNSHIFT, so it is never cancelled.
 //   - NPC right-click: 4.3.4's CGPlayer_C::HandleOnRightClick cancels a form
 //     without SHAPESHIFT_FORM_FLAG_CAN_INTERACT in place of
 //     ERR_CANT_INTERACT_SHAPESHIFTED, before its range check, so we do the
@@ -206,10 +207,43 @@ bool CanAutoDismount(const void *unit) {
     return IsActivePlayer(unit) && !OnTaxi(unit) && Enabled(g_autoDismount);
 }
 
-// 4.3.4 CGUnit_C::CanAutoUnshift.
+// SpellShapeshiftForm flags that 3.3.5 and 4.4.2 give (both DBCs parsed)
+// but 1.12's rows lack, for the forms a 1.12 player can take:
+//   - CAN_INTERACT on Cat (1), Travel (3), Aquatic (4), Bear (5), Dire Bear
+//     (8), Ghost Wolf (16), and 11, which Turtle uses for Swift Travel Form;
+//   - NO_AUTO_UNSHIFT on Spirit of Redemption (32, 0x4100 there, 0 in 1.12).
+// Every other 1.12 player form either has the same flags or has flag bit 0
+// (Moonkin, Tree of Life, the stances, Stealth), so IsShapeShifted does not
+// count it and no gate or form rung tests it.
+struct LaterFormFlags {
+    int form;
+    uint32_t flags;
+};
+constexpr LaterFormFlags kLaterFormFlags[] = {
+    {1, Offsets::SHAPESHIFT_FORM_FLAG_CAN_INTERACT},
+    {3, Offsets::SHAPESHIFT_FORM_FLAG_CAN_INTERACT},
+    {4, Offsets::SHAPESHIFT_FORM_FLAG_CAN_INTERACT},
+    {5, Offsets::SHAPESHIFT_FORM_FLAG_CAN_INTERACT},
+    {8, Offsets::SHAPESHIFT_FORM_FLAG_CAN_INTERACT},
+    {11, Offsets::SHAPESHIFT_FORM_FLAG_CAN_INTERACT},
+    {16, Offsets::SHAPESHIFT_FORM_FLAG_CAN_INTERACT},
+    {32, Offsets::SHAPESHIFT_FORM_FLAG_NO_AUTO_UNSHIFT},
+};
+
+uint32_t AddedFormFlags(const void *unit) {
+    const int form = Form(unit);
+    for (const LaterFormFlags &entry : kLaterFormFlags) {
+        if (entry.form == form)
+            return entry.flags;
+    }
+    return 0;
+}
+
+// 4.3.4 CGUnit_C::CanAutoUnshift, on the later clients' NO_AUTO_UNSHIFT.
 bool CanAutoUnshift(const void *unit) {
     return IsActivePlayer(unit) && !OnTaxi(unit) && Enabled(g_autoUnshift) &&
-           (FormFlags(unit) & Offsets::SHAPESHIFT_FORM_FLAG_NO_AUTO_UNSHIFT) == 0;
+           ((FormFlags(unit) | AddedFormFlags(unit)) &
+            Offsets::SHAPESHIFT_FORM_FLAG_NO_AUTO_UNSHIFT) == 0;
 }
 
 int StandState(const void *unit) {
@@ -244,32 +278,20 @@ char IsShapeShifted(const void *unit) {
     return reinterpret_cast<IsShapeShifted_t>(Offsets::FUN_UNIT_IS_SHAPESHIFTED)(unit);
 }
 
-// The forms whose SpellShapeshiftForm row has SHAPESHIFT_FORM_FLAG_CAN_-
-// INTERACT in 3.3.5 and 4.4.2 (both DBCs parsed) but not in 1.12: Cat (1),
-// Travel (3), Aquatic (4), Bear (5), Dire Bear (8), Ghost Wolf (16), and 11,
-// which Turtle uses for Swift Travel Form. Every other 1.12 form either has
-// the flag (Shadowform) or has flag bit 0 (Moonkin, Tree of Life, the
-// stances, Stealth), so IsShapeShifted does not count it and no gate tests
-// it. No 1.12 server tests the form on an NPC or object interaction
-// (vmangos / tortoise-wow CanInteractWithNPC and the use handlers), so the
-// client gates are the only refusal.
-constexpr int kLaterInteractForms[] = {1, 3, 4, 5, 8, 11, 16};
-
-bool HasLaterInteractFlag(int form) {
-    for (const int id : kLaterInteractForms) {
-        if (id == form)
-            return true;
-    }
-    return false;
-}
-
 // The gates' test after IsShapeShifted: the form row's interact flag. With
 // autoUnshift on, a form reads the flag that the later clients give it, so
-// the form stays on for the forms that can interact there.
+// the form stays on for the forms that can interact there. No 1.12 server
+// tests the form on an NPC or a plain object use (vmangos / tortoise-wow
+// CanInteractWithNPC, the use handlers, and no form spell's AuraInterrupt-
+// Flags has the use bit 0x800), so the client gates are the only refusal.
+// A locked object opens by a spell instead, which the server's CheckCast
+// form test refuses on 1.12's spell data (Opening 6478 keeps NOT_SHAPESHIFT,
+// which 3.3.5 dropped), so the cast's form rung must still unshift there.
 bool FormCanInteract(const void *unit) {
     if ((FormFlags(unit) & Offsets::SHAPESHIFT_FORM_FLAG_CAN_INTERACT) != 0)
         return true;
-    return Enabled(g_autoUnshift) && HasLaterInteractFlag(Form(unit));
+    return Enabled(g_autoUnshift) &&
+           (AddedFormFlags(unit) & Offsets::SHAPESHIFT_FORM_FLAG_CAN_INTERACT) != 0;
 }
 
 // True when the gate would refuse and autoUnshift takes the form off instead.