perf: optimize data loading across Config, System, Profiles, and Billing tabs (#678)

* perf(model): optimize model tab load speed with two-phase fetch and loadQuick

* perf: optimize data loading across Config, System, Profiles, and Billing tabs

* chore: remove leftover bottom nav references and unused updatePrimaryScreens

* style: fix ktlint violations in Config/Profiles/Billing ViewModels

- property/argument-list wrapping for async(...) calls
- multiline-expression wrapping for async blocks
- remove unused import in ConfigViewModel
- break long error-message string literals to stay under 120 cols

---------

Co-authored-by: M57 <Hy4ri@users.noreply.github.com>

app/src/test/java/com/m57/hermescontrol/NavigationControllerTest.kt

@@ -191,7 +191,7 @@ class NavigationControllerTest {
         assertNull(NavigationController.backStack)
     }
 
-    // ── primaryScreens and updatePrimaryScreens ───────────────────────────
+    // ── primaryScreens ────────────────────────────────────────────────────
 
     @Test
     fun `isPrimaryScreen returns true for default screens`() {
@@ -208,22 +208,4 @@ class NavigationControllerTest {
         assertFalse("LogsScreen should NOT be primary", NavigationController.isPrimaryScreen(LogsScreen))
         assertFalse("ConfigScreen should NOT be primary", NavigationController.isPrimaryScreen(ConfigScreen))
     }
-
-    @Test
-    fun `updatePrimaryScreens replaces the full screen set`() {
-        NavigationController.updatePrimaryScreens(setOf(ProfilesScreen, SystemScreen))
-
-        assertTrue("ProfilesScreen should now be primary", NavigationController.isPrimaryScreen(ProfilesScreen))
-        assertTrue("SystemScreen should still be primary", NavigationController.isPrimaryScreen(SystemScreen))
-
-        // Old defaults should no longer be primary
-        assertFalse("ChatScreen should no longer be primary", NavigationController.isPrimaryScreen(ChatScreen))
-        assertFalse("SkillsScreen should no longer be primary", NavigationController.isPrimaryScreen(SkillsScreen))
-        assertFalse("SettingsScreen should no longer be primary", NavigationController.isPrimaryScreen(SettingsScreen))
-
-        // Reset to defaults to avoid test pollution
-        NavigationController.updatePrimaryScreens(
-            setOf(ChatScreen, SkillsScreen, CronJobsScreen, SystemScreen, SettingsScreen),
-        )
-    }
 }