[ENG-2059] Remove search mode from WUI

[dexhorthy]

Summary

Removed all search functionality from the HumanLayer WUI application as per ENG-2059 requirements.

Changes

• Removed SessionTableSearch component from the session table
• Removed "/" key binding that opened search modal
• Simplified command palette to only support command mode
• Cleaned up Redux state management (removed searchQuery state)
• Updated tests and demo components to reflect changes

Test plan

• [x] TypeScript compilation passes
• [x] All linting checks pass
• [x] All tests pass
• [x] Manual testing: Verify "/" key has no effect
• [x] Manual testing: Verify command palette shows only commands
• [x] Manual testing: Verify session table displays all sessions

Linear ticket: https://linear.app/humanlayer/issue/ENG-2059/remove-search-mode

---

[!IMPORTANT] Remove search functionality from HumanLayer WUI, focusing on command mode and cleaning up related state management.

• Behavior:
  • Removed SessionTableSearch component and / key binding for search.
  • Command palette in CommandPaletteMenu.tsx now only supports command mode.
  • Removed search-related state and logic from useSessionLauncher.ts and SessionTablePage.tsx.
• State Management:
  • Removed searchQuery state from Redux and related components.
  • Updated LauncherSlice and SessionSlice to reflect removal of search functionality.
• Tests:
  • Updated tests in composedDemoStore.test.ts, launcherSlice.test.ts, and sessionSlice.test.ts to remove search-related cases.
  • Adjusted demo sequences in index.tsx to align with new command-only mode.
• Misc:
  • Removed unused imports and cleaned up code in affected files.

^{This description was created by for 256bc900e20922a9e2fff7862706a9e208c277da. You can customize this summary. It will automatically update as commits are pushed.}