feat(ui): terminal, charts and low-contrast text follow the selected theme

- The lane terminal (xterm) takes its palette from the selected DARK theme —
  it stays dark in light mode, as a terminal should — and repaints live when
  the theme changes (`client/src/lib/terminalTheme.ts`).
- Charts on the Dashboard and Workflows pages draw their grid, axes, labels
  and tooltips from theme tokens instead of hardcoded near-black/white, and
  the activity heatmap ramps from the page surface to the accent, so it reads
  on every theme instead of going near-black on light ones.
- Status/brand text that only worked on dark backgrounds
  (`text-*-300/400`) gets a darker light-mode shade (`text-*-700
  dark:text-*-300`) across sessions, conversations, workflows, config and
  settings. Categorical chart colours are kept.

client/src/pages/CcConfig.tsx

@@ -970,7 +970,7 @@ type Tone =
 const TONES: Record<Tone, { iconBg: string; iconText: string; bar: string; ring: string }> = {
   sky: {
     iconBg: "bg-sky-500/10",
-    iconText: "text-sky-300",
+    iconText: "text-sky-700 dark:text-sky-300",
     bar: "bg-sky-500/40",
     ring: "ring-sky-500/20",
   },
@@ -982,7 +982,7 @@ const TONES: Record<Tone, { iconBg: string; iconText: string; bar: string; ring:
   },
   violet: {
     iconBg: "bg-violet-500/10",
-    iconText: "text-violet-300",
+    iconText: "text-violet-700 dark:text-violet-300",
     bar: "bg-violet-500/40",
     ring: "ring-violet-500/20",
   },
@@ -994,37 +994,37 @@ const TONES: Record<Tone, { iconBg: string; iconText: string; bar: string; ring:
   },
   fuchsia: {
     iconBg: "bg-fuchsia-500/10",
-    iconText: "text-fuchsia-300",
+    iconText: "text-fuchsia-700 dark:text-fuchsia-300",
     bar: "bg-fuchsia-500/40",
     ring: "ring-fuchsia-500/20",
   },
   cyan: {
     iconBg: "bg-cyan-500/10",
-    iconText: "text-cyan-300",
+    iconText: "text-cyan-700 dark:text-cyan-300",
     bar: "bg-cyan-500/40",
     ring: "ring-cyan-500/20",
   },
   pink: {
     iconBg: "bg-pink-500/10",
-    iconText: "text-pink-300",
+    iconText: "text-pink-700 dark:text-pink-300",
     bar: "bg-pink-500/40",
     ring: "ring-pink-500/20",
   },
   indigo: {
     iconBg: "bg-indigo-500/10",
-    iconText: "text-indigo-300",
+    iconText: "text-indigo-700 dark:text-indigo-300",
     bar: "bg-indigo-500/40",
     ring: "ring-indigo-500/20",
   },
   orange: {
     iconBg: "bg-orange-500/10",
-    iconText: "text-orange-300",
+    iconText: "text-orange-700 dark:text-orange-300",
     bar: "bg-orange-500/40",
     ring: "ring-orange-500/20",
   },
   teal: {
     iconBg: "bg-teal-500/10",
-    iconText: "text-teal-300",
+    iconText: "text-teal-700 dark:text-teal-300",
     bar: "bg-teal-500/40",
     ring: "ring-teal-500/20",
   },
@@ -1036,7 +1036,7 @@ const TONES: Record<Tone, { iconBg: string; iconText: string; bar: string; ring:
   },
   rose: {
     iconBg: "bg-rose-500/10",
-    iconText: "text-rose-300",
+    iconText: "text-rose-700 dark:text-rose-300",
     bar: "bg-rose-500/40",
     ring: "ring-rose-500/20",
   },
@@ -2721,7 +2721,7 @@ function CurrentConfigPanel({ sources }: { sources: CcSettingsSource[] }) {
   return (
     <div className="rounded-lg border border-border bg-surface-2">
       <div className="border-b border-border px-4 py-2.5 flex items-center gap-2">
-        <SettingsIcon className="w-3.5 h-3.5 text-violet-300/80" />
+        <SettingsIcon className="w-3.5 h-3.5 text-violet-700/80 dark:text-violet-300/80" />
         <span className="text-sm font-medium text-fg-primary">Current configuration</span>
         <span className="text-[11px] text-fg-muted ml-auto">
           {setCount} option{setCount !== 1 ? "s" : ""} set · the rest use defaults
@@ -3233,7 +3233,7 @@ function renderMemoryIndex(
           type="button"
           onClick={() => onJump(capturedTarget)}
           title={`${jumpTitle}: ${normalizeMemoryTarget(capturedTarget)}`}
-          className="text-teal-300 hover:text-teal-200 underline decoration-dotted underline-offset-2 hover:decoration-solid focus:outline-none focus:ring-1 focus:ring-teal-400/60 rounded-sm"
+          className="text-teal-700 dark:text-teal-300 hover:text-teal-800 dark:hover:text-teal-200 underline decoration-dotted underline-offset-2 hover:decoration-solid focus:outline-none focus:ring-1 focus:ring-teal-400/60 rounded-sm"
         >
           {label}
         </button>
@@ -3386,7 +3386,7 @@ function MemoryPanel({
       {totalAuto > 0 && (
         <section className="pt-1">
           <div className="flex items-center gap-2 mb-1">
-            <BookOpen className="w-3.5 h-3.5 text-teal-300" />
+            <BookOpen className="w-3.5 h-3.5 text-teal-700 dark:text-teal-300" />
             <h3 className="text-[11px] font-semibold uppercase tracking-wider text-fg-secondary">
               {t("memory.autoTitle")}
             </h3>
@@ -3499,7 +3499,7 @@ function MemoryProjectGroup({
               open ? "" : "-rotate-90"
             }`}
           />
-          <FolderTree className="w-3.5 h-3.5 text-teal-300 flex-shrink-0" />
+          <FolderTree className="w-3.5 h-3.5 text-teal-700 dark:text-teal-300 flex-shrink-0" />
           <span className="font-mono text-xs text-fg-secondary truncate flex-1 min-w-0">
             {project}
           </span>
@@ -3618,7 +3618,7 @@ function MemoryIndexCard({
   return (
     <div className="rounded-md border border-teal-500/20 bg-teal-500/5">
       <div className="flex items-center gap-2 px-3 py-1.5 border-b border-teal-500/15">
-        <BookOpen className="w-3 h-3 text-teal-300 flex-shrink-0" />
+        <BookOpen className="w-3 h-3 text-teal-700 dark:text-teal-300 flex-shrink-0" />
         <span className="font-mono text-[11px] text-fg-secondary truncate flex-1 min-w-0">
           {item.name}
         </span>