feat(player): #5 LocalPlayerState — Stam/Mana wired through PlayerDescription

Closes ISSUES.md #5. The Vitals devtools window now draws three bars
(HP / Stamina / Mana) once the server sends the first PlayerDescription
(0x0013), instead of HP only. Built test-first per CLAUDE.md TDD rule —
16 new tests went red before the implementation went in.

New AcDream.Core.Player.LocalPlayerState (cache):
  - {CurrentStamina, MaxStamina, CurrentMana, MaxMana} as uint? — null
    until first received.
  - StaminaPercent / ManaPercent: 0..1 fraction or null when either
    field is missing or max is zero. Clamps to 1.0 if current > max
    (server can briefly report this during buff transitions).
  - OnPlayerDescription preserves any previously known good value when
    an incoming field is null — partial profiles don't wipe state.
  - Changed event for future subscribers.

GameEventWiring.WireAll:
  - New optional 6th parameter: LocalPlayerState? localPlayer = null.
    Existing 5-arg call sites still work; without the parameter the new
    PlayerDescription handler still parses + feeds the spellbook but
    skips the cache update.
  - PlayerDescription (0x0013) shares AppraiseInfo wire format with
    IdentifyObjectResponse (0x00C9) per AppraiseInfoParser docstring,
    so the new handler reuses the existing parser and pulls
    CreatureProfile.{Stamina, StaminaMax, Mana, ManaMax}.
  - Player's full learned spellbook also lands here (previously only
    item-scoped Identify responses fed the spellbook).

VitalsVM:
  - Constructor adds optional LocalPlayerState? parameter (default null
    keeps every existing caller compiling).
  - StaminaPercent / ManaPercent now read through to LocalPlayerState
    every access — no VM-side caching, so a server-side delta to the
    cache surfaces next frame without any explicit refresh.

GameWindow:
  - Public readonly LocalPlayer field alongside Combat / Chat / Items /
    SpellBook so plugins + future panels can bind directly.
  - WireAll call updated to pass LocalPlayer.
  - VitalsVM construction passes LocalPlayer so the existing
    VitalsPanel automatically picks up the two new bars.

Test counts:
  - AcDream.Core.Tests:           550 → 561  (+11 LocalPlayerStateTests)
  - AcDream.UI.Abstractions.Tests: 23 →  26  (+3 VitalsVM through-cache)
  - AcDream.Core.Net.Tests:       192 → 194  (+2 PlayerDescription wiring)
  - Total:                        765 → 781

Build: 0 warnings, 0 errors.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/AcDream.Core/Player/LocalPlayerState.cs

@@ -0,0 +1,79 @@
+namespace AcDream.Core.Player;
+
+/// <summary>
+/// Cache of the local player's stamina + mana absolute values, populated
+/// from the <c>CreatureProfile</c> blob inside <c>PlayerDescription
+/// (0x0013)</c>. Health stays in <see cref="AcDream.Core.Combat.CombatState"/>
+/// because it has its own delta opcode (<c>UpdateHealth 0x01C0</c>); stam
+/// and mana don't, so without this cache <c>VitalsVM</c> can't surface
+/// percent-of-max bars even though the parser already decodes the
+/// absolute values.
+///
+/// <para>
+/// Filed by issue <c>#5</c> in <c>docs/ISSUES.md</c>. Once future delta
+/// opcodes for stam/mana arrive (or are recognised in the existing event
+/// stream) they update through the same <see cref="OnPlayerDescription"/>
+/// surface — keep the cache the single point of truth so VM consumers
+/// don't have to subscribe to multiple sources.
+/// </para>
+/// </summary>
+public sealed class LocalPlayerState
+{
+    /// <summary>Current stamina (absolute), or <c>null</c> if never received.</summary>
+    public uint? CurrentStamina { get; private set; }
+
+    /// <summary>Max stamina (absolute), or <c>null</c> if never received.</summary>
+    public uint? MaxStamina { get; private set; }
+
+    /// <summary>Current mana (absolute), or <c>null</c> if never received.</summary>
+    public uint? CurrentMana { get; private set; }
+
+    /// <summary>Max mana (absolute), or <c>null</c> if never received.</summary>
+    public uint? MaxMana { get; private set; }
+
+    /// <summary>Fires after any field update via <see cref="OnPlayerDescription"/>.</summary>
+    public event Action<LocalPlayerState>? Changed;
+
+    /// <summary>
+    /// Stamina as a 0..1 fraction, or <c>null</c> when either current or max
+    /// is missing or max is zero. Clamps to 1.0 if current &gt; max (which
+    /// the server can briefly report during buff transitions).
+    /// </summary>
+    public float? StaminaPercent => Percent(CurrentStamina, MaxStamina);
+
+    /// <summary>
+    /// Mana as a 0..1 fraction, or <c>null</c> when either current or max
+    /// is missing or max is zero. Same clamp rules as
+    /// <see cref="StaminaPercent"/>.
+    /// </summary>
+    public float? ManaPercent => Percent(CurrentMana, MaxMana);
+
+    /// <summary>
+    /// Apply a slice of the latest <c>CreatureProfile</c>. Each field is
+    /// nullable: <c>null</c> means "no information" — preserve any previously
+    /// known good value rather than wipe it. Fires <see cref="Changed"/> once
+    /// after the update.
+    /// </summary>
+    public void OnPlayerDescription(
+        uint? currentStamina,
+        uint? maxStamina,
+        uint? currentMana,
+        uint? maxMana)
+    {
+        if (currentStamina.HasValue) CurrentStamina = currentStamina.Value;
+        if (maxStamina.HasValue)     MaxStamina     = maxStamina.Value;
+        if (currentMana.HasValue)    CurrentMana    = currentMana.Value;
+        if (maxMana.HasValue)        MaxMana        = maxMana.Value;
+        Changed?.Invoke(this);
+    }
+
+    private static float? Percent(uint? current, uint? max)
+    {
+        if (current is not uint c) return null;
+        if (max is not uint m || m == 0) return null;
+        float r = (float)c / m;
+        if (r < 0f) r = 0f;
+        else if (r > 1f) r = 1f;
+        return r;
+    }
+}