Rebrand remaining user-visible Grok strings to Kigi/Kimi

The welcome hero subtitle still read "Thanks for trying Grok Build";
theme display names, the NO_COLOR/COLORTERM diagnostics notes, the
permission notification title, the self-update restart hints, and the
clipboard-wrap protocol marker all still said Grok. Canonical theme keys
(groknight/grokday) are unchanged — only display strings move.

crates/codegen/kigi-tui/src/settings/defs.rs

@@ -46,12 +46,12 @@ const THEME_CHOICES: &[EnumChoice] = &[
     },
     EnumChoice {
         canonical: "groknight",
-        display: "Grok Night",
+        display: "Kigi Night",
         description: "Neutral dark with magenta accent.",
     },
     EnumChoice {
         canonical: "grokday",
-        display: "Grok Day",
+        display: "Kigi Day",
         description: "Light theme for bright environments.",
     },
     EnumChoice {
@@ -295,12 +295,12 @@ const SCREEN_MODE_CHOICES: &[EnumChoice] = &[
 const CONCRETE_THEME_CHOICES: &[EnumChoice] = &[
     EnumChoice {
         canonical: "groknight",
-        display: "Grok Night",
+        display: "Kigi Night",
         description: "Neutral dark with magenta accent.",
     },
     EnumChoice {
         canonical: "grokday",
-        display: "Grok Day",
+        display: "Kigi Day",
         description: "Light theme for bright environments.",
     },
     EnumChoice {

crates/codegen/kigi-tui/src/settings/registry.rs

@@ -74,7 +74,7 @@ impl SettingCategory {
 pub struct EnumChoice {
     /// Canonical persisted value (e.g. `"groknight"`).
     pub canonical: &'static str,
-    /// Display label shown in the chooser (e.g. `"Grok Night"`).
+    /// Display label shown in the chooser (e.g. `"Kigi Night"`).
     pub display: &'static str,
     /// Sub-text shown in the chooser sheet (e.g. `"Dark + magenta accent"`).
     pub description: &'static str,