docs: update grep descriptions for passthrough behavior

INSTALL.md

@@ -281,7 +281,7 @@ cp ~/.claude/settings.json.bak ~/.claude/settings.json
 ```bash
 rtk ls .              # Compact tree view
 rtk read file.rs      # Optimized reading
-rtk grep "pattern" .  # Grouped search results
+rtk grep "pattern" .  # Filtered search results (file:line:content, --no-ignore-vcs)
 ```
 
 ### Git

README.md

@@ -146,7 +146,7 @@ rtk read file.rs                # Smart file reading
 rtk read file.rs -l aggressive  # Signatures only (strips bodies)
 rtk smart file.rs               # 2-line heuristic code summary
 rtk find "*.rs" .               # Compact find results
-rtk grep "pattern" .            # Grouped search results
+rtk grep "pattern" .            # Filtered search results (file:line:content, --no-ignore-vcs)
 rtk diff file1 file2            # Condensed diff
 ```
 

README_es.md

@@ -108,7 +108,7 @@ Cuatro estrategias:
 rtk ls .                        # Arbol de directorios optimizado
 rtk read file.rs                # Lectura inteligente
 rtk find "*.rs" .               # Resultados compactos
-rtk grep "pattern" .            # Busqueda agrupada por archivo
+rtk grep "pattern" .            # Resultados filtrados (file:line:content, --no-ignore-vcs)
 ```
 
 ### Git

README_fr.md

@@ -119,7 +119,7 @@ rtk ls .                        # Arbre de repertoires optimise
 rtk read file.rs                # Lecture intelligente
 rtk read file.rs -l aggressive  # Signatures uniquement
 rtk find "*.rs" .               # Resultats compacts
-rtk grep "pattern" .            # Resultats groupes par fichier
+rtk grep "pattern" .            # Resultats filtres (file:line:content, --no-ignore-vcs)
 rtk diff file1 file2            # Diff condense
 ```
 

README_ja.md

@@ -108,7 +108,7 @@ git status  # 自動的に rtk git status に書き換え
 rtk ls .                        # 最適化されたディレクトリツリー
 rtk read file.rs                # スマートファイル読み取り
 rtk find "*.rs" .               # コンパクトな検索結果
-rtk grep "pattern" .            # ファイル別グループ化検索
+rtk grep "pattern" .            # フィルタリング検索 (file:line:content, --no-ignore-vcs)
 ```
 
 ### Git

README_ko.md

@@ -108,7 +108,7 @@ git status  # 자동으로 rtk git status로 재작성
 rtk ls .                        # 최적화된 디렉토리 트리
 rtk read file.rs                # 스마트 파일 읽기
 rtk find "*.rs" .               # 컴팩트한 검색 결과
-rtk grep "pattern" .            # 파일별 그룹화 검색
+rtk grep "pattern" .            # 필터링된 검색 결과 (file:line:content, --no-ignore-vcs)
 ```
 
 ### Git

README_zh.md

@@ -109,7 +109,7 @@ git status  # 自动重写为 rtk git status
 rtk ls .                        # 优化的目录树
 rtk read file.rs                # 智能文件读取
 rtk find "*.rs" .               # 紧凑的查找结果
-rtk grep "pattern" .            # 按文件分组的搜索结果
+rtk grep "pattern" .            # 过滤搜索结果 (file:line:content, --no-ignore-vcs)
 ```
 
 ### Git

docs/usage/AUDIT_GUIDE.md

@@ -271,7 +271,7 @@ Savings %       = (Saved / Input) × 100
 | `rtk vitest` | 94-99% | Show failures only |
 | `rtk find` | 75% | Tree format |
 | `rtk pnpm list` | 70-90% | Compact dependencies |
-| `rtk grep` | 70% | Truncate + group |
+| `rtk grep` | 50-90% | Filtered file:line:content, --no-ignore-vcs |
 
 ## Database Management
 

docs/usage/FEATURES.md

@@ -202,7 +202,7 @@ Supporte a la fois la syntaxe RTK et la syntaxe native `find` (`-name`, `-type`,
 
 ### `rtk grep` -- Recherche dans le contenu
 
-**Objectif :** Remplace `grep` et `rg` avec une sortie groupee par fichier, tronquee.
+**Objectif :** Remplace `grep` et `rg`. Sortie toujours filtree au format `file:line:content` (troncature des lignes longues, plafonds par fichier et global). Utilise `--no-ignore-vcs` pour inclure les fichiers ignores par `.gitignore`, tout en respectant `.ignore`/`.rgignore`.
 
 **Syntaxe :**
 ```bash