refactor: move configs and hooks to global locations for reusability

Move previously nested configs and hooks to global src/ folders to make
them reusable across the application, reduce nesting, and establish
clearer organization patterns.

**New Global Structure:**
- src/config/theme-options.ts (moved from appearance/config/)
- src/config/api-providers.ts (moved from api-keys/config/)
- src/hooks/use-scroll-tracking.ts (moved from settings-view/hooks/)

**Changes:**
- Move theme-options.ts to src/config/ - app-wide theme configuration
- Move api-provider-config.ts to src/config/api-providers.ts - global API config
- Move use-scroll-tracking.ts to src/hooks/ - reusable scroll navigation hook
- Make useScrollTracking generic and more flexible with options object
- Update all imports across settings-view components
- Remove duplicate api-provider-config.ts from shared/ folder
- Remove empty config/ folders (appearance/config, api-keys/config)

**Benefits:**
✅ Single source of truth for themes and API providers
✅ Reusable scroll tracking hook available globally
✅ Cleaner structure with less nesting
✅ Better discoverability for developers
✅ No duplicate configuration files

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

app/src/config/theme-options.ts

@@ -0,0 +1,88 @@
+import {
+  type LucideIcon,
+  Atom,
+  Cat,
+  Eclipse,
+  Flame,
+  Ghost,
+  Moon,
+  Radio,
+  Snowflake,
+  Sparkles,
+  Sun,
+  Terminal,
+  Trees,
+} from "lucide-react";
+import { Theme } from "@/components/views/settings-view/shared/types";
+
+export interface ThemeOption {
+  value: Theme;
+  label: string;
+  Icon: LucideIcon;
+  testId: string;
+}
+
+export const themeOptions: ReadonlyArray<ThemeOption> = [
+  { value: "dark", label: "Dark", Icon: Moon, testId: "dark-mode-button" },
+  { value: "light", label: "Light", Icon: Sun, testId: "light-mode-button" },
+  {
+    value: "retro",
+    label: "Retro",
+    Icon: Terminal,
+    testId: "retro-mode-button",
+  },
+  {
+    value: "dracula",
+    label: "Dracula",
+    Icon: Ghost,
+    testId: "dracula-mode-button",
+  },
+  {
+    value: "nord",
+    label: "Nord",
+    Icon: Snowflake,
+    testId: "nord-mode-button",
+  },
+  {
+    value: "monokai",
+    label: "Monokai",
+    Icon: Flame,
+    testId: "monokai-mode-button",
+  },
+  {
+    value: "tokyonight",
+    label: "Tokyo Night",
+    Icon: Sparkles,
+    testId: "tokyonight-mode-button",
+  },
+  {
+    value: "solarized",
+    label: "Solarized",
+    Icon: Eclipse,
+    testId: "solarized-mode-button",
+  },
+  {
+    value: "gruvbox",
+    label: "Gruvbox",
+    Icon: Trees,
+    testId: "gruvbox-mode-button",
+  },
+  {
+    value: "catppuccin",
+    label: "Catppuccin",
+    Icon: Cat,
+    testId: "catppuccin-mode-button",
+  },
+  {
+    value: "onedark",
+    label: "One Dark",
+    Icon: Atom,
+    testId: "onedark-mode-button",
+  },
+  {
+    value: "synthwave",
+    label: "Synthwave",
+    Icon: Radio,
+    testId: "synthwave-mode-button",
+  },
+];