Paragon: add Builds catalog (saved loadouts with pet park/unpark)

Server-side Character Advancement now stores named, icon-tagged build
recipes (panel-purchased spells + per-spec talent ranks) and atomically
swaps between them by snapshotting the active build, refunding AE/TE
through HandleParagonReset{Talents,Abilities}, and re-spending on the
target recipe. Hunter pets attached to a build are parked to
PET_SAVE_NOT_IN_SLOT (mirroring HandleStableSwapPet) so name, talents,
and exp survive swaps; non-hunter pets (warlock demon, DK ghoul, mage
water elemental) are NOT parked because the engine resummons them from
a fresh template each cast.

New PARAA verbs: Q BUILDS / C BUILD NEW / C BUILD EDIT / C BUILD
DELETE / C BUILD FAVORITE / C BUILD LOAD. The catalog is pushed on
login and after every mutation as a single addon message.

Schema (mod-paragon migration 2026_05_10_03.sql):
- character_paragon_builds (build_id PK, guid, name, icon, is_favorite,
  pet_number, created_at)
- character_paragon_build_spells (build_id, spell_id)
- character_paragon_build_talents (build_id, spec, talent_id, rank)
- character_paragon_active_build (guid PK, build_id)

The talent recipe table is spec-keyed so a build remembers tank/dps
dual-spec layouts independently. Swaps are blocked while in combat.

Co-authored-by: Cursor <cursoragent@cursor.com>

modules/mod-paragon/data/sql/db-characters/updates/2026_05_10_03.sql

@@ -0,0 +1,62 @@
+-- mod-paragon Character Advancement: Build catalog (saved loadouts).
+-- ----------------------------------------------------------------------------
+-- A "build" is a named, icon-tagged loadout of panel-purchased spells and
+-- talent ranks. Each Paragon character can save many builds and swap
+-- between them via the Builds page in the Character Advancement panel.
+--
+-- Swap workflow (see HandleBuildLoad in Paragon_Builds.cpp):
+--   1. If a build is currently active, snapshot the player's current
+--      panel-purchased spells + per-spec talent ranks into that build's
+--      recipe rows (overwriting the stored recipe).
+--   2. If the active build's hunter pet is currently summoned, unsummon
+--      it to PET_SAVE_NOT_IN_SLOT and store its `pet_number` on the
+--      active build row so it can be restored on swap-back.
+--   3. Reset all panel-bought abilities and talents (refunding AE/TE).
+--   4. Re-buy each spell + talent in the target build's recipe (charging
+--      AE/TE; aborts if insufficient AE/TE -- player keeps refunded
+--      currency in that case and active becomes NULL).
+--   5. Move the target build's parked pet (if any) back to current.
+--   6. Update active_build pointer.
+--
+-- Pet ownership: a parked pet sits in `character_pet` with slot=100
+-- (PET_SAVE_NOT_IN_SLOT), exactly like the engine's stable-master
+-- offload, but tied to the build via `pet_number` instead of any
+-- in-game stable slot. Build deletion drops the parked pet rows
+-- entirely (PET_SAVE_AS_DELETED equivalent) -- player is warned.
+-- ----------------------------------------------------------------------------
+
+CREATE TABLE IF NOT EXISTS `character_paragon_builds` (
+    `build_id`    INT UNSIGNED   NOT NULL AUTO_INCREMENT,
+    `guid`        INT UNSIGNED   NOT NULL COMMENT 'characters.guid',
+    `name`        VARCHAR(32)    NOT NULL,
+    `icon`        VARCHAR(64)    NOT NULL DEFAULT 'INV_Misc_QuestionMark',
+    `is_favorite` TINYINT UNSIGNED NOT NULL DEFAULT 0,
+    `pet_number`  INT UNSIGNED   NULL COMMENT 'character_pet.id of parked hunter pet, NULL when no pet bound to this build',
+    `created_at`  TIMESTAMP      NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    PRIMARY KEY (`build_id`),
+    KEY `idx_guid` (`guid`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci
+    COMMENT='mod-paragon: saved Character Advancement build catalog';
+
+CREATE TABLE IF NOT EXISTS `character_paragon_build_spells` (
+    `build_id` INT UNSIGNED NOT NULL,
+    `spell_id` INT UNSIGNED NOT NULL,
+    PRIMARY KEY (`build_id`, `spell_id`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci
+    COMMENT='mod-paragon: per-build recipe -- panel-purchased spells';
+
+CREATE TABLE IF NOT EXISTS `character_paragon_build_talents` (
+    `build_id`  INT UNSIGNED      NOT NULL,
+    `spec`      TINYINT UNSIGNED  NOT NULL COMMENT '0 = primary spec, 1 = secondary (dual spec)',
+    `talent_id` SMALLINT UNSIGNED NOT NULL,
+    `rank`      TINYINT UNSIGNED  NOT NULL,
+    PRIMARY KEY (`build_id`, `spec`, `talent_id`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci
+    COMMENT='mod-paragon: per-build recipe -- panel-purchased talent ranks per spec';
+
+CREATE TABLE IF NOT EXISTS `character_paragon_active_build` (
+    `guid`     INT UNSIGNED NOT NULL COMMENT 'characters.guid',
+    `build_id` INT UNSIGNED NOT NULL COMMENT 'character_paragon_builds.build_id (per-character active pointer)',
+    PRIMARY KEY (`guid`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci
+    COMMENT='mod-paragon: pointer to whichever build is currently loaded (one row per Paragon character)';