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>

tests/AcDream.Core.Tests/Player/LocalPlayerStateTests.cs

@@ -0,0 +1,144 @@
+using AcDream.Core.Player;
+
+namespace AcDream.Core.Tests.Player;
+
+/// <summary>
+/// Tests for <see cref="LocalPlayerState"/> — the cache that retains
+/// stamina / mana absolute + max values from <c>PlayerDescription
+/// (0x0013)</c>'s embedded <c>CreatureProfile</c>. Health stays in
+/// <see cref="AcDream.Core.Combat.CombatState"/>; this class only
+/// covers the vitals that don't have a dedicated delta opcode in
+/// our currently-wired event set.
+/// </summary>
+public sealed class LocalPlayerStateTests
+{
+    [Fact]
+    public void Defaults_AllVitalsNull_PercentsNull()
+    {
+        var s = new LocalPlayerState();
+
+        Assert.Null(s.CurrentStamina);
+        Assert.Null(s.MaxStamina);
+        Assert.Null(s.CurrentMana);
+        Assert.Null(s.MaxMana);
+        Assert.Null(s.StaminaPercent);
+        Assert.Null(s.ManaPercent);
+    }
+
+    [Fact]
+    public void OnPlayerDescription_PopulatesFields_FromValidValues()
+    {
+        var s = new LocalPlayerState();
+
+        s.OnPlayerDescription(currentStamina: 50, maxStamina: 100,
+                              currentMana: 150, maxMana: 200);
+
+        Assert.Equal(50u, s.CurrentStamina);
+        Assert.Equal(100u, s.MaxStamina);
+        Assert.Equal(150u, s.CurrentMana);
+        Assert.Equal(200u, s.MaxMana);
+    }
+
+    [Fact]
+    public void StaminaPercent_IsCurrentOverMax_InZeroToOneRange()
+    {
+        var s = new LocalPlayerState();
+        s.OnPlayerDescription(currentStamina: 50, maxStamina: 100,
+                              currentMana: null, maxMana: null);
+
+        Assert.Equal(0.5f, s.StaminaPercent!.Value, precision: 3);
+    }
+
+    [Fact]
+    public void ManaPercent_IsCurrentOverMax_InZeroToOneRange()
+    {
+        var s = new LocalPlayerState();
+        s.OnPlayerDescription(currentStamina: null, maxStamina: null,
+                              currentMana: 75, maxMana: 100);
+
+        Assert.Equal(0.75f, s.ManaPercent!.Value, precision: 3);
+    }
+
+    [Fact]
+    public void StaminaPercent_NullWhenMaxIsZero_AvoidsDivByZero()
+    {
+        var s = new LocalPlayerState();
+        s.OnPlayerDescription(currentStamina: 0, maxStamina: 0,
+                              currentMana: null, maxMana: null);
+
+        Assert.Null(s.StaminaPercent);
+    }
+
+    [Fact]
+    public void ManaPercent_NullWhenMaxIsZero_AvoidsDivByZero()
+    {
+        var s = new LocalPlayerState();
+        s.OnPlayerDescription(currentStamina: null, maxStamina: null,
+                              currentMana: 0, maxMana: 0);
+
+        Assert.Null(s.ManaPercent);
+    }
+
+    [Fact]
+    public void StaminaPercent_Null_WhenOnlyCurrentKnown()
+    {
+        var s = new LocalPlayerState();
+        s.OnPlayerDescription(currentStamina: 50, maxStamina: null,
+                              currentMana: null, maxMana: null);
+        // Max never received → percent indeterminate.
+        Assert.Null(s.StaminaPercent);
+    }
+
+    [Fact]
+    public void StaminaPercent_Null_WhenOnlyMaxKnown()
+    {
+        var s = new LocalPlayerState();
+        s.OnPlayerDescription(currentStamina: null, maxStamina: 100,
+                              currentMana: null, maxMana: null);
+        // Current never received → percent indeterminate.
+        Assert.Null(s.StaminaPercent);
+    }
+
+    [Fact]
+    public void StaminaPercent_ClampsToOne_WhenCurrentExceedsMax()
+    {
+        var s = new LocalPlayerState();
+        // Server can momentarily report current > max during buff transitions.
+        s.OnPlayerDescription(currentStamina: 150, maxStamina: 100,
+                              currentMana: null, maxMana: null);
+
+        Assert.Equal(1f, s.StaminaPercent!.Value);
+    }
+
+    [Fact]
+    public void Changed_EventFires_WhenAnyVitalUpdates()
+    {
+        var s = new LocalPlayerState();
+        int fires = 0;
+        s.Changed += _ => fires++;
+
+        s.OnPlayerDescription(currentStamina: 50, maxStamina: 100,
+                              currentMana: 75, maxMana: 200);
+
+        Assert.Equal(1, fires);
+    }
+
+    [Fact]
+    public void OnPlayerDescription_PreservesPreviousField_WhenIncomingValueIsNull()
+    {
+        // CreatureProfile occasionally has nullable fields if the server
+        // sends a partial profile — the cache should preserve known-good
+        // values rather than wipe them. Stamina set first, then a Mana-only
+        // update should not clear Stamina.
+        var s = new LocalPlayerState();
+        s.OnPlayerDescription(currentStamina: 50, maxStamina: 100,
+                              currentMana: null, maxMana: null);
+        s.OnPlayerDescription(currentStamina: null, maxStamina: null,
+                              currentMana: 75, maxMana: 200);
+
+        Assert.Equal(50u, s.CurrentStamina);
+        Assert.Equal(100u, s.MaxStamina);
+        Assert.Equal(75u, s.CurrentMana);
+        Assert.Equal(200u, s.MaxMana);
+    }
+}