p1-4: scaffold kb-normalize crate

Add the workspace member, `Cargo.toml` with the §8-allowed dep set
(kb-core, kb-parse-types, kb-config, serde, serde_json_canonicalizer,
blake3, unicode-normalization, time, anyhow, tracing) and a stubbed
`build_canonical_document` that pins the public signature plus
`doc_id` derivation. `kb-parse-md` is permitted only as a *dev*-dep so
the integration snapshot test (added later in this series) can drive
a fixture through the real parser without violating the production
boundary — `cargo tree -p kb-normalize --depth 1 --edges normal`
confirms no parser implementation appears in the regular dep tree.

`id_for_doc` and `id_for_block` are re-exported from kb-core (which
holds the canonical recipe per §4.2); kb-normalize is the canonical
*entry point* per design §8.

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

Cargo.lock

@@ -577,6 +577,24 @@ dependencies = [
  "unicode-normalization",
 ]
 
+[[package]]
+name = "kb-normalize"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "blake3",
+ "kb-config",
+ "kb-core",
+ "kb-parse-md",
+ "kb-parse-types",
+ "serde",
+ "serde_json",
+ "serde_json_canonicalizer",
+ "time",
+ "tracing",
+ "unicode-normalization",
+]
+
 [[package]]
 name = "kb-parse-md"
 version = "0.1.0"