feat(p10-1a-1): kebab-parse-code crate (lang + repo + skip)

Tasks 5-8: new `kebab-parse-code` crate with three infrastructure modules
for the code ingest framework. Ships lang.rs (extension→language identifier
mapping), repo.rs (.git walk-up via gix 0.70 for RepoMeta), and skip.rs
(BUILTIN_BLACKLIST, is_generated_file, is_oversized). 14 integration tests
across three test files, all passing; clippy -D warnings clean.

Note: gix pinned to 0.70 (not 0.83 as originally suggested) because 0.83
fails to compile against Rust 1.94.1 due to non-exhaustive match patterns
in gix-hash. 0.70 resolves cleanly and has identical head_name/head_id API.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

crates/kebab-parse-code/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "kebab-parse-code"
+version       = { workspace = true }
+edition       = { workspace = true }
+license       = { workspace = true }
+
+[dependencies]
+anyhow      = { workspace = true }
+gix         = { workspace = true }
+kebab-core  = { path = "../kebab-core" }
+
+[dev-dependencies]
+tempfile = { workspace = true }