Make the branded GoSentry theme the default.

Co-authored-by: Cursor <cursoragent@cursor.com>

docs/CHANGELOG.md

@@ -38,6 +38,10 @@ dragged.**
 
 **Settings:**
 
+- **The branded GoSentry theme is now the default.** Fresh installs, the
+  **Defaults** button, and configs that omit `theme` all open in the teal/amber
+  look; users who prefer Fyne's built-in theme can still pick **Default** in
+  Settings.
 - The **Save / Cancel / Restore defaults** row sits 4 px from the left edge, as
   its layout always intended, rather than 8.
 - The caption column is as wide as the widest caption instead of a fixed width,

docs/TESTS.md

@@ -514,7 +514,7 @@ Tests the branded theme and the stored theme choice.
 |------|---------|
 | `TestGoSentryThemeBrandColors` | Verifies the brand colors land on the semantically correct `ColorName`s in both the light and dark variants. |
 | `TestGoSentryThemeDelegatesUnbrandedColors` | Verifies unbranded color names fall through to the base theme rather than rendering transparent. |
-| `TestThemeForChoice` | Verifies the GoSentry choice yields the branded primary and every other value — including the empty legacy one — yields the default theme. |
+| `TestThemeForChoice` | Verifies the GoSentry choice and the empty legacy value yield the branded primary; only the explicit default choice yields Fyne's built-in theme. |
 | `TestThemeLabelRoundTrip` | Verifies the dropdown labels round-trip and that the empty value maps to the Default label rather than a blank option. |
 
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