refactor(console): phase 1 — extract pure ConsoleTextLayout (wrap/hit-test/selection)

Lift the console's word-wrap layout, screen->text hit-testing, and selection extraction
out of ConsoleTab into a pure, ImGui-free module (console_text_layout.{h,cpp}). Text
measurement is injected via a ConsoleTextMeasure interface — production uses an
ImFont-backed impl (identical CalcWordWrapPositionA/CalcTextSizeA calls as before), while
tests drive a fixed-width stub.

- BuildConsoleLayout: per-line wrap segments + heights + cumulative Y (was inline in
  renderOutput).
- HitTestConsoleLayout: point -> (visibleRow, byte col) (was screenToTextPos).
- ExtractConsoleSelection: selected text across visible lines (was getSelectedText).
- ConsoleTab now holds a single `ConsoleLayout layout_` (replacing 4 mutable members;
  drops the dead cached_wrap_width_) and calls the pure functions.
- New unit test testConsoleTextLayout covers wrapping, multi-row hit-testing, bottom
  clamp, and filtered/unfiltered selection — the biggest previously-untested surface.

No behavior change (algorithm preserved verbatim). Full-node + lite build clean, ctest
green.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/ui/windows/console_tab.h

@@ -4,6 +4,7 @@
 
 #pragma once
 
+#include "console_text_layout.h"
 #include "../layout.h"
 #include "../../daemon/embedded_daemon.h"
 #include "../../daemon/xmrig_manager.h"
@@ -147,24 +148,12 @@ private:
     mutable int filter_match_count_ = 0;        // lines matching the text filter (for the toolbar)
     std::string context_token_;                 // hash/address under the cursor at right-click
     mutable std::vector<int> visible_indices_;  // Cached for selection mapping
-    
-    // Wrapped line height caching (for variable-height text wrapping)
-    mutable std::vector<float> wrapped_heights_;      // Height of each visible line (accounts for wrapping)
-    mutable std::vector<float> cumulative_y_offsets_; // Cumulative Y offset for each visible line
-    mutable float total_wrapped_height_ = 0.0f;       // Total height of all visible lines
-    mutable float cached_wrap_width_ = 0.0f;          // Wrap width used for cached heights
-    
-    // Sub-row layout: each visible line is split into wrap segments so
-    // selection and hit-testing know the exact screen position of every
-    // character.
-    struct WrapSegment {
-        int   byteStart;   // byte offset into ConsoleLine::text
-        int   byteEnd;     // byte offset past last char in this segment
-        float yOffset;     // Y offset of this segment relative to the line's top
-        float height;      // visual height of this segment
-    };
-    mutable std::vector<std::vector<WrapSegment>> visible_wrap_segments_; // [vi] -> segments
-    
+
+    // Wrap layout for the visible lines (segments + per-line heights + cumulative Y),
+    // recomputed each frame by the pure BuildConsoleLayout (console_text_layout.h) and
+    // consumed by the renderer + hit-testing.
+    mutable ConsoleLayout layout_;
+
     // Commands popup
     bool show_commands_popup_ = false;
 };