Merge bfloat16-senbei workspace restructure, bump to 1.1.0

Adopts the fork's workspace split (senbei-cli / senbei-crypto / senbei-io /
senbei-metadata / senbei-pe), its structured error taxonomy, entry-transform
and layout validation, PE32 dd8 key-formula selection with a skip floor, the
CRT entry-stub dd8 oracle, and the extensionless-file scan skip.

Kept from senbei on top of the restructure:
- ManagedExe detection/routing and the CLR (COR20 + BSJB) metadata restore
  in the EXE pipeline.
- The RET+int3 padding fingerprint as the primary dd8 padding signal, ahead
  of the mutated-position 0xCC fallback.
- docs/, .github/, samples/, tests/ (moved to senbei-cli/tests), and the
  web/ wasm frontend (rewired to the split crates), all of which the fork
  had dropped.
- The fork's README compatibility matrix is not taken: it names real games,
  which the public-repo hygiene rules forbid.
- The wasm32 localtime fallback in logfile and unpack_bytes_force_exe (the
  web app's trap-recovery entry point), both lost in the restructure.

Golden corpus: 35/35 byte-identical. clippy -D warnings clean; wasm32 check
clean for the full workspace.

senbei-cli/tests/common/mod.rs

@@ -0,0 +1,11 @@
+//! Shared test fixtures.
+#![allow(dead_code)]
+
+use std::path::PathBuf;
+
+/// Path to the workspace-root `samples/` — the user-managed corpus dropped in
+/// by hand. Git-ignored except its README; tests here run against whatever is
+/// present. `CARGO_MANIFEST_DIR` is `senbei-cli/`, so go one level up.
+pub fn samples_dir() -> PathBuf {
+    PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("../samples")
+}