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/src/app.rs

@@ -924,7 +924,7 @@ impl App {
             k: u32::try_from(query.k).unwrap_or(u32::MAX),
             snippet_chars: u32::try_from(self.config.search.snippet_chars).unwrap_or(u32::MAX),
             embedding_version,
-            chunker_version: self.config.chunking.chunker_version.clone(),
+            chunker_version: self.config.ingest.chunking.chunker_version.clone(),
             corpus_revision: self.sqlite.corpus_revision(),
         })
     }
@@ -1025,7 +1025,7 @@ impl App {
 fn lexical_index_version(config: &kebab_config::Config) -> IndexVersion {
     IndexVersion(format!(
         "lex:{}:fts5-v009-korean-morphological",
-        config.chunking.chunker_version
+        config.ingest.chunking.chunker_version
     ))
 }