Fix CLI display for `opencode-rag index`

[MrDoe]

opencode-rag index doesn't update the indexing progress of the files properly.

Example:

  Vector dimension:   1024
  Description LLM:  qwen2.5:3b (ollama)
Scanning: C:\Daten\Entwicklung\OpenCodeR  doc/configuration.md                         Chunking -> Description...
  doc/plugin.md                                Chunking -> Description...
  opencode-rag.example.json                    Chunking -> Description...
  opencode-rag.json                            Chunking -> Description...
  package-lock.json                            Chunking -> Description...
  package.json                                 Chunking -> Description...
  PLANNING.md                                  Chunking -> Description...
  src/api.ts                                   Chunking -> Description...
  src/cli/index.ts                             Chunking -> Description...
  src/content/reader.ts                        Chunking -> Description...
  src/core/bootstrap.ts                        Chunking -> Description...
  src/core/config.ts                           Chunking -> Description...

We want to see the live progress for each file.

[MrDoe]

Switched back to normal line-by-line display. It's safer.