feat(chat): restyle the composer as a single card (#1114)

app/src/test/java/com/m57/hermescontrol/ui/chat/ComposerPaletteTest.kt

@@ -0,0 +1,76 @@
+package com.m57.hermescontrol.ui.chat.components
+
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.luminance
+import com.m57.hermescontrol.theme.ThemePreset
+import com.m57.hermescontrol.theme.resolveColorScheme
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+/**
+ * Contrast gate for the chat composer across every preset in both modes.
+ *
+ * - Primary text and control labels (onSurface) >= 4.5:1 — WCAG AA text.
+ * - Secondary text (placeholder, reasoning level) >= 3:1 — same bar as the
+ *   full-bleed header gate in ThemePaletteTest.
+ * - Action button against the card, and its glyph against the button >= 3:1.
+ * - Flat controls and the card edge must stay visibly distinct (>= 1.15:1).
+ *   Their labels and icons carry the WCAG 1.4.11 contrast; this floor catches
+ *   presets whose surface tiers collapse (Nord's High == Highest rendered the
+ *   controls invisible).
+ */
+class ComposerPaletteTest {
+    private fun contrast(
+        a: Color,
+        b: Color,
+    ): Float {
+        val l1 = a.luminance()
+        val l2 = b.luminance()
+        return (maxOf(l1, l2) + 0.05f) / (minOf(l1, l2) + 0.05f)
+    }
+
+    private fun forEveryPresetMode(block: (String, ComposerPalette, Color) -> Unit) {
+        ThemePreset.entries.forEach { preset ->
+            listOf(true, false).forEach { dark ->
+                val scheme = resolveColorScheme(preset, darkTheme = dark)
+                block("$preset dark=$dark", composerPalette(scheme), scheme.background)
+            }
+        }
+    }
+
+    private fun assertContrast(
+        label: String,
+        a: Color,
+        b: Color,
+        min: Float,
+    ) {
+        val ratio = contrast(a, b)
+        assertTrue("$label contrast %.2f must be >= $min".format(ratio), ratio >= min)
+    }
+
+    @Test
+    fun textMeetsContrastInEveryPresetMode() {
+        forEveryPresetMode { mode, p, _ ->
+            assertContrast("$mode input text/card", p.text, p.card, 4.5f)
+            assertContrast("$mode placeholder/card", p.placeholder, p.card, 3f)
+            assertContrast("$mode control label/control", p.onControl, p.control, 4.5f)
+            assertContrast("$mode reasoning level/control", p.onControlVariant, p.control, 3f)
+        }
+    }
+
+    @Test
+    fun actionButtonMeetsContrastInEveryPresetMode() {
+        forEveryPresetMode { mode, p, _ ->
+            assertContrast("$mode action/card", p.action, p.card, 3f)
+            assertContrast("$mode action glyph/action", p.onAction, p.action, 3f)
+        }
+    }
+
+    @Test
+    fun controlsAndCardEdgeStayVisibleInEveryPresetMode() {
+        forEveryPresetMode { mode, p, background ->
+            assertContrast("$mode control/card", p.control, p.card, 1.15f)
+            assertContrast("$mode card border/background", p.cardBorder, background, 1.15f)
+        }
+    }
+}

app/src/test/java/com/m57/hermescontrol/ui/chat/ComposerToolbarTest.kt

@@ -0,0 +1,35 @@
+package com.m57.hermescontrol.ui.chat.components
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+/**
+ * Unit tests for [composerModelLabel] — the label shown in the composer's
+ * model/reasoning pill. Only the "custom:" provider marker is dropped; the
+ * provider stays so the same model from different providers never collides.
+ */
+class ComposerToolbarTest {
+    @Test
+    fun composerModelLabel_keepsProviderToDisambiguateSameModel() {
+        assertEquals("openai/gpt-5.5", composerModelLabel("openai/gpt-5.5"))
+        assertEquals("copilot/gpt-5.5", composerModelLabel("copilot/gpt-5.5"))
+    }
+
+    @Test
+    fun composerModelLabel_dropsOnlyTheCustomMarker() {
+        assertEquals("my-provider/glm-5.3", composerModelLabel("custom:my-provider/glm-5.3"))
+        assertEquals("openrouter/openai/gpt-5.5", composerModelLabel("openrouter/openai/gpt-5.5"))
+    }
+
+    @Test
+    fun composerModelLabel_leavesModelTagsAndPlainIdsAlone() {
+        assertEquals("ollama/llama3:8b", composerModelLabel("ollama/llama3:8b"))
+        assertEquals("llama3:8b", composerModelLabel("llama3:8b"))
+        assertEquals("gpt-5", composerModelLabel("gpt-5"))
+    }
+
+    @Test
+    fun composerModelLabel_bareCustomMarker_fallsBackToFullId() {
+        assertEquals("custom:/glm-5.3", composerModelLabel("custom:/glm-5.3"))
+    }
+}