extract silently omits ignored directories without showing the detection summary #4965

Tested on v8 at 32e5efe.

Consider a parent Git repository with .gitignore containing Developments/. Under that directory, place a separate Git repository containing tracked source code. Running graphify extract . --code-only at the parent root respects the parent's ignore rule and can finish successfully after indexing only the parent shell.

Respecting ignore rules is expected. The problem is that the CLI reports discovered and unclassified files without surfacing the detector's existing ignored records, so the user has little indication why the nested repository is absent.

Expected: show a bounded summary of ignored paths and explain how to inspect the corpus boundary. --no-gitignore should be described specifically as bypassing VCS ignore rules; explicit .graphifyignore and --exclude rules must continue to apply.

The summary should reuse detector output and preserve directory pruning. It should not recursively walk ignored trees or automatically change which files are included.