refactor(config): v3 경로 call-site sweep (kebab-app/kebab-eval/kebab-parse-image)

부모 경로에 .ingest 삽입(leaf 구조체 불변). src + 테스트 call-site 전부.
kebab-cli 테스트의 v2 TOML fixture 는 from_file 자동변환(T6) 경로 검증용으로 유지.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

crates/kebab-app/tests/schema_report.rs

@@ -14,8 +14,8 @@ fn minimal_config(data_dir: &std::path::Path, workspace_root: &std::path::Path)
     config.storage.model_dir = data_dir.join("models").to_string_lossy().into_owned();
     config.models.embedding.provider = "none".to_string();
     config.models.embedding.dimensions = 0;
-    config.chunking.target_tokens = 80;
-    config.chunking.overlap_tokens = 20;
+    config.ingest.chunking.target_tokens = 80;
+    config.ingest.chunking.overlap_tokens = 20;
     config
 }