Feature: nine themes that imitate a physical medium, plus a readability floor for every theme

.gitattributes

@@ -0,0 +1,9 @@
+# Scoped deliberately to the bundled fonts rather than declaring rules for the whole repo:
+# a repo-wide text/eol policy would rewrite line endings across every existing file, which is
+# its own change with its own review. This only guarantees the one thing that would silently
+# corrupt an asset — a font is binary, and any newline "normalisation" applied to it produces a
+# file that still has the right name and no longer renders.
+*.ttf binary
+*.otf binary
+*.woff binary
+*.woff2 binary

CHANGELOG.md

@@ -16,6 +16,23 @@ for every approved plan. Desktop's version follows the engine generation, so it
 0.15.0.
 
 ### Added
+- **Nine themes that imitate a physical medium, not just a colour scheme.** Alongside the existing
+  e-ink and CRT looks, MandoCode Desktop now ships a monochrome amber terminal, a vacuum-fluorescent
+  panel, a vector scope, a passive-matrix LCD, a Solari split-flap board, a cyanotype blueprint, a
+  two-ink risograph print, continuous-feed printer paper, and microfiche. Each reproduces how its
+  medium actually made an image rather than only borrowing its colours — the LCD ghosts instead of
+  glowing, the split-flap board can only show uppercase because a flap carries one printed
+  character, and the cyanotype is a negative, so emphasis is a whiter stroke rather than a heavier
+  one. The theme list is ordered so neighbours share a mechanism, which keeps it skimmable now that
+  there are twenty-five entries.
+- **Your chat background can match the theme.** Themes that imitate a screen or a printing process
+  also process your background image the way that medium would have reproduced it — quantised to a
+  panel's few shades, rendered as amber phosphor, or laid down as two-ink halftone. On by default,
+  with a switch in Settings → Appearance to keep the picture in full colour. It affects only those
+  themes, and only when a background is set.
+- **The MandoCode wordmark has its own typeface.** The name in the top-left is now set in Permanent
+  Marker, bundled with the app rather than fetched from a font service, so it renders identically
+  offline. It takes each theme's accent colour, so it re-inks itself as you switch themes.
 - **Watch the agent's shell commands run.** The terminal panel gains a read-only tab per agent
   showing every command that agent runs — the command and the folder it runs in, its output line by
   line as it arrives, and whether it finished, failed, or was killed for taking too long. A long
@@ -192,6 +209,18 @@ for every approved plan. Desktop's version follows the engine generation, so it
   a sticky header, or the suggestion list a field opens when it is filled.
 
 ### Fixed
+- **Secondary text is readable in every theme.** Timestamps, file paths, status lines and the hints
+  under headings were below the accessibility contrast floor in half the shipped themes — several
+  faithfully so, since palettes like Dracula and One Dark ship famously faint comment colours
+  upstream. Those palettes are unchanged; the text is now lifted just far enough to clear the floor,
+  blended toward each theme's own text colour so it stays that theme's shade rather than drifting
+  grey. A theme that was already readable is left exactly as it was. Themes viewed through an
+  overlay, such as the CRT tube, are held to a higher bar, because scanlines take contrast the
+  palette's own numbers do not account for.
+- **The CRT theme's phosphor glow follows the text it surrounds.** Every glyph glowed the same
+  blue regardless of its colour, so red errors carried a blue halo. On a real tube the glow is the
+  phosphor being excited, so error text now glows red and success green. Code blocks keep a tighter
+  glow, since a full halo turns syntax highlighting into a smear.
 - **The "no agents open" message stays readable over a chat background image.** With a background
   image set, closing the last agent left the message painted straight onto the picture, where a
   busy or light image could make it hard to read. The message now sits in a translucent card — the

THIRD-PARTY-NOTICES.txt

@@ -14,6 +14,17 @@ highlight.js — https://highlightjs.org
   Copyright (c) 2006, Ivan Sagalaev
   License: BSD 3-Clause (Appendix C)
 
+--------------------------------------------------------------------------
+Bundled fonts (shipped in Assets/fonts, used for the application wordmark)
+--------------------------------------------------------------------------
+
+Permanent Marker — https://fonts.google.com/specimen/Permanent+Marker
+  Copyright (c) 2010 Font Diner, Inc.
+  License: Apache License 2.0 (Appendix D)
+  The unmodified font file ships with its full license text alongside it, at
+  Assets/fonts/LICENSE.txt. Upstream publishes no NOTICE file for this family,
+  so section 4(d) of the license imposes no further attribution.
+
 --------------------------------------------------------------------------
 .NET package dependencies (compiled into the application)
 --------------------------------------------------------------------------
@@ -152,3 +163,26 @@ INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 POSSIBILITY OF SUCH DAMAGE.
+
+--------------------------------------------------------------------------
+Appendix D — Apache License 2.0 (Permanent Marker)
+--------------------------------------------------------------------------
+
+Licensed under the Apache License, Version 2.0 (the "License"); you may not
+use this file except in compliance with the License. You may obtain a copy of
+the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+License for the specific language governing permissions and limitations under
+the License.
+
+The complete, unabridged license text is distributed with the font itself, at
+Assets/fonts/LICENSE.txt, and is installed alongside the application.
+
+Apache-2.0 is a permissive, non-copyleft license. Including this font does not
+place any condition on the terms of MandoCode Desktop's own source, which
+remains under the MIT License (see LICENSE).

src/MandoCode.Desktop.Tests/MandoCode.Desktop.Tests.csproj

@@ -60,6 +60,8 @@
     <Compile Include="..\MandoCode.Desktop\Services\StableCollection.cs" Link="src\StableCollection.cs" />
     <Compile Include="..\MandoCode.Desktop\Services\AgentCommandFormat.cs" Link="src\AgentCommandFormat.cs" />
     <Compile Include="..\MandoCode.Desktop\Services\AgentCommandLog.cs" Link="src\AgentCommandLog.cs" />
+    <Compile Include="..\MandoCode.Desktop\Services\ColorMath.cs" Link="src\ColorMath.cs" />
+    <Compile Include="..\MandoCode.Desktop\Services\UiTheme.cs" Link="src\UiTheme.cs" />
     <Compile Include="..\MandoCode.Desktop\Services\ConversationLog.cs" Link="src\ConversationLog.cs" />
     <!-- History's full-text matching + snippet extraction. Pure (text in, match out); the file reads
          and caching live in ConversationTextCache, which is NOT compiled here because it touches

src/MandoCode.Desktop.Tests/ThemeReadabilityTests.cs

@@ -0,0 +1,99 @@
+using MandoCode.Desktop.Services;
+using Xunit;
+
+namespace MandoCode.Desktop.Tests;
+
+/// <summary>
+/// Secondary text — timestamps, paths, status lines, the hint under a heading — is still text, and
+/// half the shipped palettes authored it below the WCAG AA floor. The palettes stay as authored
+/// (most are faithful to upstream schemes); UiTheme.ReadableDim is what makes them legible. The
+/// point of the sweep below is the NEXT theme: one added with a too-faint Dim fails here instead of
+/// shipping.
+/// </summary>
+public class ThemeReadabilityTests
+{
+    public static TheoryData<string> ThemeNames()
+    {
+        var data = new TheoryData<string>();
+        foreach (var t in UiTheme.All) data.Add(t.Name);
+        return data;
+    }
+
+    private static UiTheme Theme(string name) => UiTheme.All.Single(t => t.Name == name);
+
+    [Theory]
+    [MemberData(nameof(ThemeNames))]
+    public void EveryThemesSecondaryTextClearsTheFloor(string name)
+    {
+        var t = Theme(name);
+        var ratio = ColorMath.Contrast(t.ReadableDim, t.Background);
+        // A CRT theme is read through its own overlay, so it is held to the higher floor.
+        var floor = t.Crt ? ColorMath.AaNormalTextThroughGlass : ColorMath.AaNormalText;
+
+        Assert.True(ratio >= floor,
+            $"{name}: dim text is {ratio:F2}:1 against its background (floor {floor}:1)");
+    }
+
+    [Fact]
+    public void OverlaidThemesAreHeldToAHigherFloorThanPlainOnes()
+    {
+        // The point of the CRT floor is that it BINDS — if the tube themes happened to clear the
+        // ordinary floor anyway, this whole mechanism would be decoration.
+        var overlaid = UiTheme.All.Where(t => t.Crt).ToList();
+        Assert.NotEmpty(overlaid);
+
+        foreach (var t in overlaid)
+        {
+            Assert.True(ColorMath.Contrast(t.ReadableDim, t.Background) >= ColorMath.AaNormalTextThroughGlass,
+                $"{t.Name}: dim text does not clear the through-glass floor");
+        }
+        Assert.True(ColorMath.AaNormalTextThroughGlass > ColorMath.AaNormalText);
+    }
+
+    [Theory]
+    [MemberData(nameof(ThemeNames))]
+    public void EveryThemesBodyTextClearsTheFloor(string name)
+    {
+        // ReadableDim blends toward Text and stops there, so body text being readable is the
+        // assumption that makes the lift terminate. Asserted rather than assumed.
+        var t = Theme(name);
+        var ratio = ColorMath.Contrast(t.Text, t.Background);
+
+        Assert.True(ratio >= ColorMath.AaNormalText,
+            $"{name}: body text is {ratio:F2}:1 against its background");
+    }
+
+    [Theory]
+    [MemberData(nameof(ThemeNames))]
+    public void AlreadyReadablePalettesAreLeftAlone(string name)
+    {
+        // The lift is a correction, not a restyle: a theme that authored a legible Dim must come
+        // through byte-identical, or switching themes would quietly repaint palettes that were fine.
+        var t = Theme(name);
+        var floor = t.Crt ? ColorMath.AaNormalTextThroughGlass : ColorMath.AaNormalText;
+        if (ColorMath.Contrast(t.Dim, t.Background) < floor) return;
+
+        Assert.Equal(t.Dim, t.ReadableDim);
+    }
+
+    [Fact]
+    public void TheLiftIsTheSmallestOneThatWorks()
+    {
+        // Walking to the first passing step keeps a nudged palette recognisably itself. A lift that
+        // overshot would wash every faint theme toward the same grey.
+        const string bg = "#282A36", text = "#F8F8F2", faint = "#6272A4";   // Dracula
+        var lifted = ColorMath.Readable(faint, bg, text, ColorMath.AaNormalText);
+
+        Assert.True(ColorMath.Contrast(lifted, bg) >= ColorMath.AaNormalText);
+        Assert.True(ColorMath.Contrast(lifted, bg) < ColorMath.AaNormalText + 1.0,
+            "overshot: the lift should stop at the first step that clears the floor");
+        Assert.NotEqual(text, lifted);   // nudged toward the text colour, not replaced by it
+    }
+
+    [Fact]
+    public void ContrastMatchesKnownWcagValues()
+    {
+        Assert.Equal(21.0, ColorMath.Contrast("#000000", "#FFFFFF"), 2);
+        Assert.Equal(1.0, ColorMath.Contrast("#808080", "#808080"), 2);
+    }
+}