feat(cli): kebab config migrate 서브커맨드 + wire config_migration.v1

- Cmd::Config { Migrate { --dry-run } }, --json 시 config_migration.v1.
- wire_config_migration (ConfigMigrationReport 가 schema_version 자체 보유).
- schema.rs WIRE_SCHEMAS 에 config_migration.v1 등록 + JSON schema 파일.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

crates/kebab-app/src/schema.rs

@@ -108,6 +108,7 @@ const WIRE_SCHEMAS: &[&str] = &[
     "doc_summary.v1",
     "chunk_inspection.v1",
     "doctor.v1",
+    "config_migration.v1",
     "ingest_report.v1",
     "ingest_progress.v1",
     "reset_report.v1",

crates/kebab-cli/src/main.rs

@@ -60,6 +60,12 @@ enum Cmd {
         force: bool,
     },
 
+    /// config.toml 관리 (스키마 마이그레이션 등).
+    Config {
+        #[command(subcommand)]
+        what: ConfigWhat,
+    },
+
     /// Scan the workspace and ingest new/updated documents.
     Ingest {
         /// Workspace root override.
@@ -346,6 +352,16 @@ enum Cmd {
     },
 }
 
+#[derive(Subcommand, Debug)]
+enum ConfigWhat {
+    /// 기존 config.toml 을 새 스키마로 마이그레이션(빠진 섹션 추가 + 멱등 + .bak 백업).
+    Migrate {
+        /// 변경만 출력하고 파일은 수정하지 않는다.
+        #[arg(long)]
+        dry_run: bool,
+    },
+}
+
 #[derive(Subcommand, Debug)]
 enum ListWhat {
     /// List documents currently indexed.
@@ -1310,6 +1326,42 @@ fn run(cli: &Cli) -> anyhow::Result<()> {
             Ok(())
         }
 
+        Cmd::Config { what } => match what {
+            ConfigWhat::Migrate { dry_run } => {
+                let report =
+                    kebab_app::config_migrate_with_config_path(cli.config.as_deref(), *dry_run)?;
+                if cli.json {
+                    println!(
+                        "{}",
+                        serde_json::to_string(&wire::wire_config_migration(&report))?
+                    );
+                } else if !report.changed {
+                    println!(
+                        "config 이미 최신입니다 (schema v{}).",
+                        report.to_schema_version
+                    );
+                } else {
+                    let verb = if report.dry_run { "변경 예정" } else { "적용됨" };
+                    println!(
+                        "config 마이그레이션 {verb}: v{} → v{} ({} changes)",
+                        report.from_schema_version,
+                        report.to_schema_version,
+                        report.changes.len()
+                    );
+                    for c in &report.changes {
+                        println!("  - [{:?}] {} — {}", c.kind, c.path, c.detail);
+                    }
+                    if let Some(bak) = &report.backup_path {
+                        println!("백업: {bak}");
+                    }
+                    if report.dry_run {
+                        println!("(--dry-run: 파일 미수정. 적용하려면 --dry-run 없이 재실행)");
+                    }
+                }
+                Ok(())
+            }
+        },
+
         Cmd::Doctor => {
             let report = kebab_app::doctor_with_config_path(cli.config.as_deref())?;
             if cli.json {

crates/kebab-cli/src/wire.rs

@@ -225,6 +225,12 @@ pub fn wire_bulk_search_item(item: &kebab_core::BulkSearchItem) -> Value {
     v
 }
 
+/// `config_migration.v1` 직렬화. `ConfigMigrationReport` 가 `schema_version`
+/// 필드를 자체 보유하므로(doctor 와 동일) 그대로 직렬화한다.
+pub fn wire_config_migration(r: &kebab_app::ConfigMigrationReport) -> Value {
+    serde_json::to_value(r).expect("ConfigMigrationReport serializes")
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

docs/wire-schema/v1/config_migration.v1.schema.json

@@ -0,0 +1,38 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "title": "config_migration.v1",
+  "description": "Result of `kebab config migrate` — schema reconciliation of a user's config.toml.",
+  "type": "object",
+  "required": [
+    "schema_version",
+    "config_path",
+    "dry_run",
+    "from_schema_version",
+    "to_schema_version",
+    "changed",
+    "changes"
+  ],
+  "properties": {
+    "schema_version": { "const": "config_migration.v1" },
+    "config_path": { "type": "string" },
+    "dry_run": { "type": "boolean" },
+    "from_schema_version": { "type": "integer" },
+    "to_schema_version": { "type": "integer" },
+    "changed": { "type": "boolean" },
+    "backup_path": { "type": ["string", "null"] },
+    "changes": {
+      "type": "array",
+      "items": {
+        "type": "object",
+        "required": ["kind", "path", "detail"],
+        "properties": {
+          "kind": {
+            "enum": ["added_section", "added_key", "removed_deprecated"]
+          },
+          "path": { "type": "string" },
+          "detail": { "type": "string" }
+        }
+      }
+    }
+  }
+}