refactor(ui): retire ChatLogWindow and the v1.5.6 chat-window layer

The legacy ChatLogWindow.cs and its tightly coupled neighbours are gone:
PayloadHandler, Popout, ChatInputBar, AutoCompleteInfo, AutoTellTabTint,
the three tab-icon helpers, the old Ui/StatusBar and Ui/SymbolPicker
behind the components-layer replacements, HellionStyle + helpers, the
CompactInputSubmitter test mirror and the QuickPickerSelfTestStep. The
new component layer (MainWindow + the five components + GlobalStyleScope)
now drives the whole chat surface.

InputPreview, CommandHelpWindow and Debugger lose their ChatLogWindow
backref. The first two are skeleton windows for now — DrawConditions
always returns false until the new chat layer exposes equivalent state.
Debugger keeps the current-tab and vanilla-chat blocks; the payload
counters are explicitly marked offline. DbViewer renders Sender/Content
columns as plain TextValue strings instead of the removed DrawChunks.

GameFunctions.Chat and GameFunctions.KeybindManager keep the hook
plumbing intact but mark every ChatLogWindow.Activated /
ChangeTabDelta / TellSpecial site as offline so the FFXIV-side
integration still compiles and runs without an Activated entry point.
TypingIpc.BuildState reports the IPC state as not-typing / not-focused
until the new chat layer surfaces real focus and buffer state again.

Plugin.cs Draw uses StyleEngine.GlobalStyleScope.Push for the per-frame
theme push and stops calling BeginFrame / FinalizeFrame / HideStateCheck
/ DefaultText through the dead window. ImGuiUtil drops PostPayload +
WrapText + the surrounding word-wrap pipeline. PluginHostFactory and
PluginLifecycle drop the legacy DI singletons and AddWindow entries.

Build is clean and csharpier is clean across the trimmed 131-file tree.

HellionChat/Ui/AutoTellTabTint.cs

@@ -1,70 +0,0 @@
-namespace HellionChat.Ui;
-
-// Deterministic hash-based color and icon tinting for Auto-Tell sidebar tabs.
-// Same tell partner (name+world) always produces the same color and icon across
-// sessions. Pure string logic, no Dalamud dependency — testable without game refs.
-internal static class AutoTellTabTint
-{
-    // Fallback for invalid input (empty name or world=0). White matches
-    // TextPrimary default so the sidebar stays visually consistent.
-    public const uint Fallback = 0xFFFFFFFFu;
-
-    // 12 saturated mid-bright colors from the built-in theme pool, readable
-    // on dark backgrounds. Collision risk is low at realistic 1-5 active tells.
-    // RGBA format, matching ColourUtil.RgbaToAbgr convention.
-    public static readonly IReadOnlyList<uint> Palette = new uint[]
-    {
-        0x00BED2FFu, // Arctic Cyan
-        0xF97316FFu, // Ember Orange
-        0xB585FFFFu, // Light Cosmic Purple
-        0xE374E8FFu, // Bloom Magenta
-        0x5DD39EFFu, // Mint Green
-        0xF0AD4EFFu, // Warning Yellow
-        0xE85C6AFFu, // Coral
-        0x5CB85CFFu, // Status Green
-        0x6278FFFFu, // Bloom Blue
-        0xC9982EFFu, // Warm Gold
-        0x9CCB7CFFu, // Soft Sage
-        0xE85D04FFu, // Deep Ember
-    };
-
-    public static uint For(string name, uint world)
-    {
-        if (string.IsNullOrEmpty(name) || world == 0)
-            return Fallback;
-
-        // Mask to positive range so modulo always yields a valid index.
-        var key = $"{name}@{world}";
-        var hash = (uint)(key.GetHashCode() & 0x7FFFFFFF);
-        return Palette[(int)(hash % Palette.Count)];
-    }
-
-    // 7 visually distinct FA glyphs that make sense in a tell context.
-    // Excludes cog/comment/users — those read as system or group tabs.
-    public static readonly IReadOnlyList<string> IconPool = new[]
-    {
-        "envelope",
-        "star",
-        "heart",
-        "bell",
-        "bookmark",
-        "flag",
-        "fire",
-    };
-
-    // "envelope" matches the tell context better than the old hardcoded "clock".
-    public const string IconFallback = "envelope";
-
-    public static string IconFor(string name, uint world)
-    {
-        if (string.IsNullOrEmpty(name) || world == 0)
-            return IconFallback;
-
-        // Reversed key ("world@name") gives icon and color independent variation
-        // so the same tell partner doesn't always get the same color+icon pair.
-        // 7 icons x 12 colors = 84 distinct combinations.
-        var key = $"{world}@{name}";
-        var hash = (uint)(key.GetHashCode() & 0x7FFFFFFF);
-        return IconPool[(int)(hash % IconPool.Count)];
-    }
-}