Theme System Refactor (#6)

# Dashboard State Lift + Theme System Refactor

## Summary

Refactored dashboard state ownership, centralized theme semantics, and simplified component styling across the application.

## Changes

### Dashboard State Refactor

* Moved dashboard state management from `Dashboard.view` into `Dashboard.tsx`
* Added centralized `DashboardState` initialization in parent container
* Introduced memoized dashboard state setter callbacks:

  * `toggleFlow`
  * `setFlow`
  * `togglePeriodType`
  * `toggleComparison`
  * `setSelectedPeriodId`
  * `setSelectedGroupKey`
* Added `DashboardStateSetters` memoized object for prop-driven state management
* Removed `onFlowChange` callback pattern
* Converted dashboard component into stateless view layer
* Renamed component export flow:

  * `Dashboard.tsx` → removed
  * `Dashboard.view.tsx` → primary implementation

### Dashboard Models Cleanup

* Removed legacy palette configuration interfaces:

  * `ColorDefinition`
  * `ThemeAwarePalette`
* Removed config-level style palette support from `DashboardConfig`
* Renamed `DashboardProps` → `DashboardViewProps`
* Added reusable `ColorScheme` interface
* Simplified component color contract:

  * `primary`
  * `surface`
  * `text`

### Theme Architecture Refactor

* Moved `AppTheme.tsx` into `shared-theme`
* Added centralized semantic theme system
* Introduced `themeConfig.ts` with semantic tokens:

  * surface
  * border
  * text
* Added `semantic` extension to MUI theme typing
* Added `flows` palette extension:

  * outflows
  * inflows
* Centralized flow colors inside theme primitives
* Added CSS semantic variables:

  * `--bg-page`
  * `--bg-card`
  * `--bg-elevated`
  * `--border-default`
  * `--border-subtle`
  * `--text-primary`
  * `--text-secondary`
  * `--text-muted`

### Theme Mode Improvements

* Added explicit `ColorMode` type
* Expanded `ColorModeContext`:

  * `mode`
  * `setMode`
  * `toggleColorMode`
* Added `CssBaseline`
* Added configurable `defaultMode`
* Simplified dark theme palette handling
* Standardized dark surfaces and shadows
* Reduced excessive dark-mode glow/shadow intensity

### Dashboard UI Styling Improvements

* Replaced hardcoded dashboard palette config with theme palette usage
* Updated dashboard background gradients to use alpha-based semantic colors
* Replaced `colorScheme.light` usage with `colorScheme.surface`
* Standardized border usage with theme divider tokens
* Removed manual dark-mode conditional styling where redundant
* Simplified card and progress styling logic

### Shared Theme Customization Cleanup

Updated customization layers for improved consistency:

* `inputs`
* `navigation`
* `feedback`
* `surfaces`

Key improvements:

* Reduced dark-mode contrast harshness
* Unified divider usage
* Replaced hardcoded grayscale backgrounds with semantic surfaces
* Simplified hover and active state styling
* Reduced shadow intensity across components
* Improved dark-mode readability and layering

### Home Page Styling Cleanup

* Replaced manual RGBA handling with `alpha()` utility
* Improved dark-mode glassmorphism consistency
* Updated CTA hover shadow to use theme primary color

### Miscellaneous Cleanup

* Updated imports to new theme structure
* Removed unused legacy color mode components:

  * `ColorModeIconDropdown.tsx`
  * `ColorModeSelect.tsx`
* Removed dashboard config style palette definitions
* Simplified flow-based color derivation logic

## Result

* Cleaner separation of stateful vs presentational dashboard logic
* Centralized semantic theming system
* Consistent dark/light mode behavior
* Reduced styling duplication
* Improved maintainability and extensibility of theme architecture
* Simplified dashboard component contracts
* Better UI consistency across surfaces and controls

Reviewed-on: #6
Co-authored-by: Vishesh 'ironeagle' Bangotra <aetoskia@gmail.com>
Co-committed-by: Vishesh 'ironeagle' Bangotra <aetoskia@gmail.com>

src/Home.tsx

@@ -1,10 +1,12 @@
 import * as React from "react";
 import { Box, Typography, Button, Container, Stack } from "@mui/material";
+import { useTheme, alpha } from "@mui/material/styles";
 import { useNavigate } from "react-router-dom";
 import ArrowForwardIcon from "@mui/icons-material/ArrowForward";
 
 export default function Home() {
   const navigate = useNavigate();
+  const theme = useTheme();
 
   return (
     <Box
@@ -46,14 +48,13 @@ export default function Home() {
           sx={{
             p: { xs: 4, md: 8 },
             backdropFilter: "blur(20px)",
-            backgroundColor: (theme) => 
-               theme.palette.mode === "dark" ? "rgba(255, 255, 255, 0.03)" : "rgba(255, 255, 255, 0.6)",
+            backgroundColor: (t) => alpha(t.palette.common.white, t.palette.mode === "dark" ? 0.04 : 0.6),
             border: "1px solid",
             borderColor: "divider",
             borderRadius: 4,
-            boxShadow: (theme) =>
-              theme.palette.mode === "dark"
-                ? "0 8px 32px 0 rgba(0, 0, 0, 0.37)"
+            boxShadow: (t) =>
+              t.palette.mode === "dark"
+                ? "0 8px 32px 0 rgba(0, 0, 0, 0.5)"
                 : "0 8px 32px 0 rgba(31, 38, 135, 0.07)",
           }}
         >
@@ -94,7 +95,7 @@ export default function Home() {
                 transition: "transform 0.2s ease-in-out, box-shadow 0.2s",
                 "&:hover": {
                   transform: "translateY(-3px)",
-                  boxShadow: "0 8px 20px rgba(236,72,153,0.4)",
+                  boxShadow: (t) => `0 8px 20px ${alpha(t.palette.primary.main, 0.4)}`,
                 },
               }}
             >