fix(desktop): satisfy slash metadata typecheck

[helix4u]

What does this PR do?

Fixes the Desktop TypeScript build failure introduced by the slash command metadata change in #39289. SlashItemMetadata extends Record<string, string>, but rawText was declared optional as string | undefined, which makes tsc -b fail with TS2411.

The metadata object always sets rawText: command, so this makes the interface match the actual runtime shape.

Related Issue

Fixes #

Support thread evidence: Windows Desktop installer failed at apps/desktop build failed (exit 1) on commit 1eeb7da2e6e5 with:

src/app/chat/composer/hooks/use-slash-completions.ts(19,3): error TS2411: Property rawText of type string | undefined is not assignable to string index type string.

Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)

Changes Made

• apps/desktop/src/app/chat/composer/hooks/use-slash-completions.ts — Changed SlashItemMetadata.rawText from optional to required so it satisfies the Record<string, string> index signature and matches the object literal that always supplies rawText: command.

How to Test

1. On origin/main at 1eeb7da2e6e5, the Windows Desktop installer log shows npm run pack failing during tsc -b with TS2411 in use-slash-completions.ts.
2. Apply this change.
3. Run cd apps/desktop && npm run type-check.

Result: npm run type-check passes locally.

Checklist

Code

• I've read the Contributing Guide
• My commit messages follow Conventional Commits (fix(scope):, feat(scope):, etc.)
• I searched for existing PRs to make sure this isn't a duplicate
• My PR contains only changes related to this fix/feature (no unrelated commits)
• I've run pytest tests/ -q and all tests pass
• I've added tests for my changes (required for bug fixes, strongly encouraged for features)
• I've tested on my platform: WSL/Linux via Desktop TypeScript build check

Documentation & Housekeeping

• I've updated relevant documentation (README, docs/, docstrings) — N/A
• I've updated cli-config.yaml.example if I added/changed config keys — N/A
• I've updated CONTRIBUTING.md or AGENTS.md if I changed architecture or workflows — N/A
• I've considered cross-platform impact (Windows, macOS) per the compatibility guide — Windows Desktop installer build failure; TypeScript-only fix
• I've updated tool descriptions/schemas if I changed tool behavior — N/A

For New Skills

N/A

Screenshots / Logs

Failing installer log excerpt from support thread:

src/app/chat/composer/hooks/use-slash-completions.ts(19,3): error TS2411: Property rawText of type string | undefined is not assignable to string index type string.

Validation run:

cd apps/desktop && npm run type-check

Passed.

[rdnot]

comfirm reproducible on windows 11 (desktop build failed due to this)