docs: Add comprehensive implementation plans for all todo items

Created detailed markdown plans for all items in todo.md:

1. 01-playwright-scaffolding.md - Base Playwright infrastructure
2. 02-magnitude-tests-comprehensive.md - Complete test coverage
3. 03-stream-ai-to-deepgram-tts.md - TTS latency optimization
4. 04-fix-galaxy-node-clicking.md - Galaxy navigation bugs
5. 05-dark-light-mode-theme.md - Dark/light mode with dynamic favicons
6. 06-fix-double-border-desktop.md - UI polish
7. 07-delete-backup-files.md - Code cleanup
8. 08-ai-transition-to-edit.md - Intelligent node creation flow
9. 09-umap-minimum-nodes-analysis.md - Technical analysis

Each plan includes:
- Detailed problem analysis
- Proposed solutions with code examples
- Manual Playwright MCP testing strategy
- Magnitude test specifications
- Implementation steps
- Success criteria

Ready to implement in sequence.

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

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

plans/06-fix-double-border-desktop.md

@@ -0,0 +1,171 @@
+# Plan: Fix Double Border on Desktop Between Sidebar and Conversation
+
+**Priority:** LOW - Visual polish
+**Dependencies:** None
+**Affects:** Desktop UI aesthetics
+
+## Overview
+
+There's a double border appearing on desktop between the sidebar and the main conversation area. This creates a visual inconsistency and needs to be fixed for a polished look.
+
+## Current Issue
+
+```
++----------+||+-------------+
+| Sidebar  |||  Main       |
+|          |||  Content    |
+|          |||             |
++----------+||+-------------+
+             ^^
+        Double border
+```
+
+## Root Cause
+
+Likely causes:
+1. Both AppShell.Navbar and AppShell.Main have borders
+2. Border-box sizing causing borders to stack
+3. Mantine default styles adding extra borders
+
+## Investigation Steps
+
+1. **Inspect current implementation**
+   ```typescript
+   // Check components/DesktopNav.tsx
+   // Check app/layout.tsx AppShell usage
+   // Check theme.ts AppShell styles
+   ```
+
+2. **Identify which elements have borders**
+   - AppShell.Navbar
+   - AppShell.Main
+   - Any wrapper components
+
+## Proposed Fixes
+
+### Option 1: Remove Border from One Side
+
+```typescript
+// app/theme.ts
+export const theme = createTheme({
+  components: {
+    AppShell: {
+      styles: {
+        navbar: {
+          borderRight: 'none', // Remove right border from navbar
+        },
+      },
+    },
+  },
+});
+```
+
+### Option 2: Use Single Shared Border
+
+```typescript
+// app/theme.ts
+export const theme = createTheme({
+  components: {
+    AppShell: {
+      styles: (theme) => ({
+        navbar: {
+          borderRight: `1px solid ${theme.colors.gray[3]}`,
+        },
+        main: {
+          borderLeft: 'none', // Remove left border from main
+        },
+      }),
+    },
+  },
+});
+```
+
+### Option 3: Use Divider Component
+
+```typescript
+// components/DesktopNav.tsx
+<Group h="100%" gap={0} wrap="nowrap">
+  <AppShell.Navbar>{/* ... */}</AppShell.Navbar>
+  <Divider orientation="vertical" />
+  <AppShell.Main>{/* ... */}</AppShell.Main>
+</Group>
+```
+
+## Testing
+
+### Manual Playwright MCP Test
+```typescript
+test('No double border between sidebar and main content', async ({ page }) => {
+  await page.goto('/chat');
+  await page.setViewportSize({ width: 1920, height: 1080 });
+
+  // Take screenshot of border area
+  const borderElement = page.locator('.mantine-AppShell-navbar');
+  await borderElement.screenshot({ path: 'border-before.png' });
+
+  // Check computed styles
+  const navbarBorder = await page.evaluate(() => {
+    const navbar = document.querySelector('.mantine-AppShell-navbar');
+    return window.getComputedStyle(navbar!).borderRight;
+  });
+
+  const mainBorder = await page.evaluate(() => {
+    const main = document.querySelector('.mantine-AppShell-main');
+    return window.getComputedStyle(main!).borderLeft;
+  });
+
+  // Only one should have a border
+  const hasDouble = navbarBorder !== 'none' && mainBorder !== 'none';
+  expect(hasDouble).toBe(false);
+});
+```
+
+### Magnitude Test
+```typescript
+import { test } from 'magnitude-test';
+
+test('Desktop sidebar has clean border', async (agent) => {
+  await agent.open('http://localhost:3000/chat');
+  await agent.act('Resize window to desktop size (1920x1080)');
+  await agent.check('Sidebar is visible');
+  await agent.check('No double border between sidebar and content');
+  await agent.check('Border is clean and single-width');
+});
+```
+
+## Implementation Steps
+
+1. **Identify current border setup**
+   - Inspect DesktopNav component
+   - Check AppShell configuration
+   - Check theme.ts
+
+2. **Choose fix approach**
+   - Decide which element keeps the border
+   - Remove border from other element
+
+3. **Implement fix**
+   - Update theme.ts or component styles
+
+4. **Test with Playwright MCP**
+   - Visual inspection
+   - Computed styles check
+
+5. **Add Magnitude test**
+
+6. **Commit and push**
+
+## Success Criteria
+
+- ✅ Only one border between sidebar and main content
+- ✅ Border is clean and single-width
+- ✅ Consistent across all pages
+- ✅ Works in both light and dark mode
+- ✅ Playwright MCP test passes
+- ✅ Magnitude test passes
+
+## Files to Update
+
+1. `app/theme.ts` - Update AppShell border styles
+2. `tests/playwright/desktop-border.spec.ts` - Manual test
+3. `tests/magnitude/desktop-border.mag.ts` - Magnitude test