Library Enter / Search 'i' 가 Inspect 진입. Doc 또는 Chunk 단일 view 로
metadata / provenance / blocks (doc) 또는 spans / text / embeddings (chunk)
6 section 을 collapsible 로 표시. Esc/q 로 originating pane 으로 복귀.

핵심:
- InspectTarget enum (`Doc(DocumentId) | Chunk(ChunkId)`).
- InspectState 본체 (`app.rs`) — target / doc / chunk / collapsed
  HashSet / scroll / return_to / needs_fetch / loading.
- `src/inspect.rs`:
  - `render_inspect` — target 종류별 render_doc / render_chunk 분기,
    section header 가 collapse marker (▾/▸) 표시. metadata.user JSON
    pretty-printed.
  - `handle_key_inspect`: j/k / Down/Up scroll. PageDown/PageUp 10 row.
    c = toggle all sections (v1 simplification). Esc/q = SwitchPane(return_to).
  - `enter_inspect(state, target, return_to)` helper — Library 와 Search
    공통 entry point.
  - run-loop hook `refresh_inspect` — needs_fetch 면 lazy
    inspect_doc_with_config / inspect_chunk_with_config.
- run.rs: Pane::Inspect arm 이 handle_key_inspect + render_inspect.
  Idle tick 마다 refresh_inspect. SwitchPane(Inspect) lazy init.
- Library: Enter 가 enter_inspect(Doc(selected)) 호출 후 SwitchPane.
- Search: 'i' (plain modifier) 가 enter_inspect(Chunk(selected_hit))
  호출 후 SwitchPane. typing 'i' (\"instance\") 와 충돌 가드.

테스트 12개 (`tests/inspect.rs`, TestBackend) — Esc 가 return_to 사용
/ q 도 동작 / j/k scroll bounds / PgUp PgDn ±10 / c 일괄 toggle / no
target hint / loading / doc view header+metadata+provenance+blocks /
collapse hides body / chunk view text+block_ids / no slot →
SwitchPane(Library) / enter_inspect helper sets fields.

Spec deviation (HOTFIXES `2026-05-02 P9-4`):
- `render_inspect<B: Backend>` generic 제거 (P9-1/2/3 와 동일).
- Search `i` 키 추가 (P9-2 spec 에 없었음, P9-4 retroactive 추가).
- `c` 일괄 collapse — spec 의 \"focus 기반 selective collapse\" 는 P+.

Docs (sync rule):
- README: TUI 행 \"4 패널\" + Quick start 코멘트.
- HANDOFF: 한 줄 요약 + Phase status (P9 3/5 → 4/5) + deviation 한 줄.
- HOTFIXES: P9-4 entry.
- tasks/p9/p9-4 status: completed.

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

@@ -0,0 +323,4 @@
+            };
+            format!("Paragraph: {trimmed}")
+        }
+        Block::Quote(q) => format!("Quote: {} chars", q.text.len()),

@@ -0,0 +407,4 @@
+            // simplify by toggling all sections").
+            toggle_all_sections(s);
+            KeyOutcome::Continue
+        }

@@ -282,0 +287,4 @@
+                // we can re-borrow `state` mutably for the inspect-side
+                // mutation below.
+                let target = crate::app::InspectTarget::Doc(doc_id);
+                crate::inspect::enter_inspect(state, target, Pane::Library);

@@ -184,0 +193,4 @@
+            if s.hits.is_empty() {
+                None
+            } else {
+                Some(s.hits[s.selected_hit].chunk_id.clone())

@@ -17,0 +19,4 @@
+**Discovered**: P9-4 implementation start.
+
+**Symptom 1 (cosmetic)**: Same shape as P9-1/2/3 — `tasks/p9/p9-4-tui-inspect.md` § Public surface declares `render_inspect<B: ratatui::backend::Backend>(...)`. ratatui 0.28's `Frame` is backend-agnostic; the generic is unused.
+

@@ -0,0 +329,4 @@
+    }
+}
+
+fn describe_block(b: &Block) -> String {

@@ -0,0 +477,4 @@
+        InspectTarget::Doc(doc_id) => {
+            let result = kebab_app::inspect_doc_with_config(cfg, &doc_id);
+            let s = state.inspect.as_mut().unwrap();
+            s.loading = false;

@@ -0,0 +242,4 @@
+    assert!(rendered.contains("Test Doc"), "title rendered");
+    assert!(rendered.contains("notes/test.md"), "doc_path rendered");
+    assert!(rendered.contains("test-parser"), "parser_version rendered");
+    assert!(rendered.contains("metadata"), "metadata section visible");