[UX] No progress feedback during `export` for large repositories

[coderabbitai]

Summary

executeExport() in src/cli/commands/export.ts iterates over all tracked files, reads each one, and then runs 6 LLM agents in parallel. For a medium-sized repository (1 000+ files) this can take several minutes with zero terminal feedback — no spinner, no progress bar, no ETA.

Impact

• Users cannot distinguish between a working but slow run and a hung/crashed process
• ora and cli-progress are already listed as dependencies but are not used here

Recommended Fix

1. Use ora for the file-collection phase: Collecting files… (342/1000)
2. Use cli-progress for the agent phase: one bar per agent showing completion
3. Print a summary line after each agent finishes (name + finding count + duration)

Backlink: #1