feat(schema): add active_parsers + active_chunkers arrays to schema.v1.models (Bug #13)

이전: schema.v1.models 가 parser_version / chunker_version 단일 값만 보고 →
multi-medium corpus (md + pdf + code Rust/Python + dockerfile + k8s + manifest)
의 version cascade audit 누락 risk.

이후: additive minor — Models struct 에 active_parsers + active_chunkers Vec<String>
추가. backward compat: 기존 단일 field 보존 (markdown default), 신규 array 는
optional (#[serde(default)] + JSON schema required 미포함).

source:
- kebab_store_sqlite::fetch_distinct_parser_versions() 가
  documents.parser_version DISTINCT + ORDER BY 반환.
- fetch_distinct_chunker_versions() 가 chunks.chunker_version 동일 pattern.
- collect_models 가 매 schema 호출마다 재계산 (cache 없음 — R-3 자동 해결).

wire schema additive only — 메이저 bump 불필요. v0.20.1 minor 로 충분.
integrations/claude-code/kebab/SKILL.md 동기 갱신.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/kebab-store-sqlite/src/store.rs

@@ -961,6 +961,51 @@ impl SqliteStore {
         }
         Ok(out)
     }
+
+    /// p20-bugfix3 Bug #13: schema.v1.models.active_parsers 의 source.
+    /// `documents.parser_version` 컬럼의 DISTINCT 값을 정렬해 반환.
+    /// 빈 corpus → 빈 Vec.
+    pub fn fetch_distinct_parser_versions(&self) -> anyhow::Result<Vec<String>> {
+        use anyhow::Context;
+        let conn = self.read_conn();
+        let mut stmt = conn
+            .prepare(
+                "SELECT DISTINCT parser_version FROM documents \
+                  WHERE parser_version IS NOT NULL AND parser_version != '' \
+                  ORDER BY parser_version",
+            )
+            .context("prepare fetch_distinct_parser_versions")?;
+        let rows = stmt
+            .query_map([], |row| row.get::<_, String>(0))
+            .context("query fetch_distinct_parser_versions")?;
+        let mut out = Vec::new();
+        for r in rows {
+            out.push(r.context("read parser_version row")?);
+        }
+        Ok(out)
+    }
+
+    /// p20-bugfix3 Bug #13: schema.v1.models.active_chunkers 의 source.
+    /// `chunks.chunker_version` 컬럼의 DISTINCT 값을 정렬해 반환.
+    pub fn fetch_distinct_chunker_versions(&self) -> anyhow::Result<Vec<String>> {
+        use anyhow::Context;
+        let conn = self.read_conn();
+        let mut stmt = conn
+            .prepare(
+                "SELECT DISTINCT chunker_version FROM chunks \
+                  WHERE chunker_version IS NOT NULL AND chunker_version != '' \
+                  ORDER BY chunker_version",
+            )
+            .context("prepare fetch_distinct_chunker_versions")?;
+        let rows = stmt
+            .query_map([], |row| row.get::<_, String>(0))
+            .context("query fetch_distinct_chunker_versions")?;
+        let mut out = Vec::new();
+        for r in rows {
+            out.push(r.context("read chunker_version row")?);
+        }
+        Ok(out)
+    }
 }
 
 /// Apply the design §5 / task-spec pragmas. Called once per connection.