refactor(rename): kb → kebab — binary, env vars, XDG paths, file renames

두 번째 commit. 사용자 facing surface (CLI binary, env vars, XDG paths)
+ 코드 안 single-letter token (`KB_`, `kb.sqlite`, `/kb/`, tracing
target) 일괄 rename. 그리고 3 개 file rename:

- 디자인 doc `2026-04-27-kb-final-form-design.md` →
  `2026-04-27-kebab-final-form-design.md`
- 최초 보고서 `kb_local_rust_report.md` → `kebab_local_rust_report.md`
- workspace ignore `.kbignore` → `.kebabignore`

## 변경

- `crates/kebab-cli/Cargo.toml`: `[[bin]] name = "kb"` → `"kebab"`.
- `crates/kebab-cli/src/main.rs`: `#[command(name = "kb", …)]` →
  `name = "kebab"`.
- 모든 `KB_*` env var (코드 + doc + 테스트) → `KEBAB_*`. apply_env
  prefix 매칭 + 30+ 개 setting 키 모두.
- XDG paths: `~/.config/kb` / `~/.local/share/kb` / `~/.cache/kb` /
  `~/.local/state/kb` → `~/.config/kebab` 등. config defaults +
  expand_path tests + paths.rs 의 hardcode 모두.
- SQLite filename: `kb.sqlite` → `kebab.sqlite` (`SQLITE_FILE` const
  + 테스트 hardcode 모두).
- tracing target: `target: "kb-*"` → `"kebab-*"` (10+ 곳).
- snapshot fixture: `.kbignore` → `.kebabignore` (`fixtures/source-fs/
  tree-1.snapshot.json` 갱신).

## 검증

- `cargo test --workspace -j 1` clean (linker OOM 회피 위해 직렬).
- `cargo clippy --workspace --all-targets -- -D warnings` clean.

다음 commit 에서 docs sweep.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

crates/kebab-llm-local/src/lib.rs

@@ -29,7 +29,7 @@
 //! - **Lazy connect.** [`OllamaLanguageModel::new`] does not hit the network;
 //!   the first error surfaces on [`LanguageModel::generate_stream`].
 //!
-//! See `docs/superpowers/specs/2026-04-27-kb-final-form-design.md` §7.2,
+//! See `docs/superpowers/specs/2026-04-27-kebab-final-form-design.md` §7.2,
 //! §6.4 (`[models.llm]`), §0 Q5 (streaming), §10 (errors), and report §11.2
 //! (Ollama protocol notes).
 

crates/kebab-llm-local/tests/integration.rs

@@ -19,8 +19,8 @@ use kebab_llm_local::{LanguageModel, OllamaLanguageModel};
 #[ignore = "requires a local Ollama daemon + pulled model"]
 fn real_ollama_streams_non_empty_response() {
     // Use whatever model the workspace defaults select. Override via the
-    // KB_MODELS_LLM_MODEL env var if you want a different one for this run
-    // (e.g. `KB_MODELS_LLM_MODEL=qwen2.5:7b-instruct cargo test ... -- --ignored`).
+    // KEBAB_MODELS_LLM_MODEL env var if you want a different one for this run
+    // (e.g. `KEBAB_MODELS_LLM_MODEL=qwen2.5:7b-instruct cargo test ... -- --ignored`).
     let cfg = Config::load(None).expect("config should load");
     let llm = OllamaLanguageModel::new(&cfg).unwrap();