docs(cli): list 'code' in --media help string + SKILL.md (Bug #7)

Why: kebab search --media code 가 v0.18.0 부터 functional support 됨
(MEDIA_KINDS 외 path 로 first-class 처리, schema.v1.media_breakdown.code
존재). 그러나 SearchArgs 의 clap doc-comment + SKILL.md line 57 의
value list 가 stale — `code` 누락. user 가 --help 만 보고 code 미지원이라
오해 가능.

Change: 2 surface 동기 — main.rs line 158-160 의 multi-line clap
doc-comment + integrations/claude-code/kebab/SKILL.md line 57.
Rust binary surface / wire schema 변경 0.

Out of scope (follow-up): crates/kebab-mcp/tools/search.rs:44,
crates/kebab-core/src/search.rs:32+52, crates/kebab-app/src/
ingest_progress.rs:69, crates/kebab-cli/tests/wire_schema_breakdowns.rs:35
도 동일 stale list 보유. spec ACCEPT (round 1c) 의 grep boundary
밖이므로 본 round 미포함.

Refs: docs/superpowers/specs/2026-05-27-v0.20-sub1-bugfix2-spec.md
§4.3 / §4.3a.

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

integrations/claude-code/kebab/SKILL.md

@@ -54,7 +54,7 @@ Input:
 
 - `mode = "hybrid"` is the default-correct choice. Use `"vector"` for semantic-only ("docs about X concept"), `"lexical"` for exact strings ("the literal flag `--foo-bar`").
 - **`max_tokens` / `snippet_chars` / `cursor` (p9-fb-34)** — agent budget controls. Set `max_tokens` to cap result wire size (chars/4 estimate); set `cursor` to the previous response's `next_cursor` to fetch the next page.
-- **p9-fb-36 filter inputs:** `tags` (string array — OR-within, AND across keys), `lang` (BCP-47 language code), `path_glob` (glob pattern matched against doc path), `trust_min` (`"primary"` | `"secondary"` | `"generated"` — includes that level and above), `media` (string array — IN-list of `"markdown"` | `"pdf"` | `"image"` | `"audio"` | `"other"`; alias `"md"` → `"markdown"`), `ingested_after` (RFC3339 UTC string), `doc_id` (exact doc UUID). AND combinator across keys. Invalid `ingested_after` or unknown `trust_min` → `error.v1.code = invalid_input`. Unknown `media` value → empty hits, no error.
+- **p9-fb-36 filter inputs:** `tags` (string array — OR-within, AND across keys), `lang` (BCP-47 language code), `path_glob` (glob pattern matched against doc path), `trust_min` (`"primary"` | `"secondary"` | `"generated"` — includes that level and above), `media` (string array — IN-list of `"markdown"` | `"pdf"` | `"image"` | `"audio"` | `"code"` | `"other"`; alias `"md"` → `"markdown"`), `ingested_after` (RFC3339 UTC string), `doc_id` (exact doc UUID). AND combinator across keys. Invalid `ingested_after` or unknown `trust_min` → `error.v1.code = invalid_input`. Unknown `media` value → empty hits, no error.
 - Output is `search_response.v1`: `{ hits: search_hit.v1[], next_cursor: string|null, truncated: bool }`. Iterate `response.hits[]` for individual hits. Key hit fields: `rank`, `score`, `doc_path`, `heading_path[]`, `section_label`, `snippet`, `citation` (line range / page), `chunk_id`.
 - **`hits[].score_kind` (p9-fb-38):** `"rrf"` (hybrid) / `"bm25"` (lexical) / `"cosine"` (vector). Declares the meaning of the top-level `score` — it is a **ranking signal**, not a confidence value. If you need a trust threshold, use `retrieval.lexical_score` (BM25 raw) / `retrieval.vector_score` (cosine raw) instead of the top-level `score`.
 - Cite back to the user as `doc_path § heading_path[-1]` so they can open the source.