feat(web): upgrade quick jump launcher

[vultuk]

Closes #104

Summary

• reuse the shared repo-launcher parser inside the / quick-jump dialog
• show recent, bookmarked, and watched quick-reopen suggestions in the dialog
• keep keyboard navigation consistent by letting explicit arrow-key selection override a typed repo target only when the user intentionally selects a suggestion

Why this improves Discofork

The slash shortcut now behaves like a real launcher instead of a bare owner/repo textbox. People can paste GitHub or Discofork repo URLs directly, reopen repos they already use on the same device, and trust that the highlighted suggestion is the repo Enter will open.

Validation

• cd web && npx bun run typecheck
• npx bun test test/repo-launcher.test.ts test/quick-jump-dialog.test.ts
• npx bun test
• cd web && npx bun run build
• npx bun run typecheck (still fails on pre-existing DOM-global errors in web/src/lib/history.ts, web/src/lib/local-storage.ts, and web/src/lib/watches.ts outside this issue)

Review gate

• reviewer-only fallback was used because the full review-changes orchestration path was unavailable in this active context
• the first review found a highlighted-vs-submitted quick-jump mismatch
• this PR includes the follow-up fix and the rerun reviewer approved the updated diff

Risks / follow-ups

• A future component-level interaction test for the dialog could complement the current helper-level regression coverage.

Exec plan

• .hermes/plans/2026-04-14-quick-jump-repo-launcher.md