[CD-1234] Add dark mode support

[igzard]

Summary

This PR implements the changes requested in YouTrack ticket CD-1234.

Ticket Summary: Add dark mode support

Description

Add dark mode support

Implement dark mode toggle for the application. Users should be able to switch between light and dark themes.

Requirements:

• Add theme toggle button in header
• Store theme preference in localStorage
• Apply dark theme styles to all components
• Ensure good contrast ratios for accessibility

Generated Implementation

╭────────────────────────────────────────────────────────────────────╮
│ │
│ Configuration Error │
│ │
│ The configuration file at /root/.claude.json contains invalid │
│ JSON. │
│ │
│ Unterminated string in JSON at position 29728 (line 301 column 7) │
│ │
│ Choose an option: │
│ ❯ 1. Exit and fix manually │
│ 2. Reset with default configuration │
│ │
╰────────────────────────────────────────────────────────────────────╯

�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[GError: Raw mode is not supported on the current process.stdin, which Ink uses as input stream by default.
Read about how to prevent this error on https://github.com/vadimdemedes/ink/#israwmodesupported
at handleSetRawMode (file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:714:3853)
at file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:723:259
at jF (file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:67:21530)
at jX (file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:67:41141)
at file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:67:39313
at $l1 (file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:61:78952)
at Immediate.Cl1 [as _onImmediate] (file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:61:79371)
at process.processImmediate (node:internal/timers:485:21)
╭────────────────────────────────────────────────────────────────────╮
│ │
│ Configuration Error │
│ │
│ The configuration file at /root/.claude.json contains invalid │
│ JSON. │
│ │
│ Unterminated string in JSON at position 29728 (line 301 column 7) │
│ │
│ Choose an option: │
│ ❯ 1. Exit and fix manually │
│ 2. Reset with default configuration │
│ │
╰────────────────────────────────────────────────────────────────────╯

�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[1A�[2K�[G
ERROR Raw mode is not supported on the current process.stdin, which Ink uses
as input stream by default.
Read about how to prevent this error on
https://github.com/vadimdemedes/ink/#israwmodesupported

• Read about how to prevent this error on
  https://github.com/vadimdemedes/ink/#israwmodesupported
  -handleSetRawM (file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/c
  ode li.js:714:3853)

(file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:723:259)

-jF (file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:67:21
530)
-jX (file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:67:41
141)

• (file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:67:3931

-$l1 (file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:61:7
8952)
-Immediate.C (file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli
1 .js:61:79371)

• process.processImmediate (node:internal/timers:485:21)

Error: Raw mode is not supported on the current process.stdin, which Ink uses as input stream by default.
Read about how to prevent this error on https://github.com/vadimdemedes/ink/#israwmodesupported
at handleSetRawMode (file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:714:3853)
at file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:723:259
at jF (file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:67:21530)
at jX (file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:67:41141)
at file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:67:39313
at $l1 (file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:61:78952)
at Immediate.Cl1 [as _onImmediate] (file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:61:79371)
at process.processImmediate (node:internal/timers:485:21)

Checklist

• Code has been tested
• Documentation has been updated if necessary
• All tests pass
• Code follows project style guidelines

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This PR was automatically generated by Billy AI Dev Bot
YouTrack Ticket: CD-1234