fix(ui): port live experience quality updates (#217)

Parse retail PrivateUpdatePropertyInt64 and route authoritative Total/Available Experience through both local-player projections so Attributes, the level meter, and Skills refresh together. Preserve the existing retail XP curve and right-align the Total XP value.

Close the user-confirmed item-give gate for #216 and record the named-retail/ACE/holtburger conformance evidence.

Co-Authored-By: Codex <noreply@openai.com>

docs/research/2026-07-13-retail-experience-update-pseudocode.md

@@ -0,0 +1,81 @@
+# Retail experience-update pipeline pseudocode
+
+**Date:** 2026-07-13
+**Scope:** live Total Experience, Unassigned Experience, and character-level XP meter
+
+## Retail oracle
+
+- `CM_Qualities::DispatchUI_PrivateUpdateInt64 @ 0x006AEAD0`
+  validates opcode `0x02CF`, then reads `sequence:u8`, `property:u32`, and
+  `value:i64` from offsets 4, 5, and 9.
+- `ClientObjMaintSystem::Handle_Qualities__PrivateUpdateInt64 @ 0x00559000`
+  applies the property to the local player's qualities through the common
+  `UpdateStat<Int64_QualityType, int64_t>` path.
+- `gmStatManagementUI::PostInit @ 0x004EFD90` registers the panel for player
+  `StatType::Int64` qualities 1 (TotalExperience), 2 (AvailableExperience),
+  6 (AvailableLuminance), and 7 (MaximumLuminance).
+- `gmStatManagementUI::Update @ 0x004F0020` calls `UpdateExperience` whenever
+  the registered player qualities refresh.
+- `gmStatManagementUI::UpdateExperience @ 0x004F0A70` reads Int64 quality 1,
+  reads Int quality `0x19` (level), derives the current and next cumulative-XP
+  thresholds, writes the total-XP and XP-to-next text, and sets meter attribute
+  `0x69` to `(totalXp - currentThreshold) / (nextThreshold - currentThreshold)`.
+
+The named top-level dispatch table routes `0x02CD` to private Int32,
+`0x02CE` to public Int32, `0x02CF` to private Int64, and `0x02D0` to public
+Int64. acdream already handled the first two and was missing `0x02CF`.
+
+## Cross-reference
+
+- ACE `GameMessagePrivateUpdatePropertyInt64` writes the same 17-byte body:
+  opcode, one-byte sequence, property id, signed 64-bit value.
+- ACE marks `PropertyInt64.TotalExperience` (1) and
+  `PropertyInt64.AvailableExperience` (2) `SendOnLogin`, and
+  `GameEventPlayerDescription` includes both in the login Int64 table.
+- holtburger
+  `crates/holtburger-protocol/src/messages/object/messages/properties.rs`
+  defines `PrivateUpdatePropertyInt64Data = UpdatePropertyInt64<false>`; its
+  generic private-property unpacker reads `u8 sequence`, no guid, `u32
+  property`, then `i64 value`.
+
+## Faithful pseudocode
+
+```text
+on top-level game message(body):
+    if body.opcode == 0x02CF:
+        require body.length >= 17
+        sequence = body.u8_at(4)       // transport ordering byte; latest value wins
+        property = body.u32_at(5)
+        value    = body.i64_at(9)
+
+        player.qualities.int64[property] = value
+        notify registered quality observers
+
+on character-stat panel update(player.qualities):
+    totalXp = qualities.int64[1]
+    level   = qualities.int32[0x19]
+    current = ExperienceToLevel(level)
+    next    = ExperienceToLevel(level + 1)
+
+    totalXpText = format(totalXp)
+    xpToNextText = format(max(0, next - totalXp))
+    xpMeter = next > current
+        ? clamp((totalXp - current) / (next - current), 0, 1)
+        : 0
+
+on skill panel update(player.qualities):
+    unassignedExperienceText = format(qualities.int64[2])
+```
+
+## Port shape
+
+1. Parse `0x02CF` as an exact typed top-level message.
+2. Publish a typed `PlayerInt64PropertyUpdated` event from `WorldSession`.
+3. Apply the update to both existing local-player projections
+   (`ClientObjectTable` and `LocalPlayerState`) so every retained UI consumer
+   observes the same authoritative server value.
+4. Keep the existing ExperienceTable calculation; it already matches
+   `UpdateExperience` and was only starved of live data.
+5. Preserve the imported retail layout and explicitly right-align only the
+   Total Experience value element (`0x10000235`); its caption remains left
+   aligned.