fix(cflite): correct fuzz binary path — fuzz/ is workspace-excluded (refs #143) (#147)

## Summary

`.clusterfuzzlite/build.sh` was copying fuzz binaries from
`./target/x86_64-unknown-linux-gnu/release/`, but `fuzz` is excluded
from the workspace (`Cargo.toml:154-157`), so cargo-fuzz writes to
`./fuzz/target/x86_64-unknown-linux-gnu/release/` instead. The cp
silently failed on the first iteration (alphabetically:
`fuzz_axiom_tracker`) and `bash -eu` exited the script.

This is why `cflite_pr.yml` has never had a green run on this repo
(`gh run list --workflow cflite_pr.yml --status success` returns
empty).

Closes #143.

## What changed

- `.clusterfuzzlite/build.sh:8` — `cp ./target/…/release/$target` → `cp
./fuzz/target/…/release/$target`
- Added a 5-line comment explaining the workspace-exclusion that
  forces this path so a future contributor doesn't "fix" it back.

## Test plan

- [ ] `cflite_pr.yml` on this PR completes the build step and either
      (a) goes green within the 5-minute fuzz budget, or (b) reaches
      the actual fuzz runtime and reports a real finding.
- [ ] No other workflow regresses (the cp change is build-script-only;
      no behavioural change to the fuzz harness, no change to fuzz
      target source or Cargo manifest).

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

Author: hyperpolymath

.clusterfuzzlite/build.sh

@@ -2,6 +2,12 @@
 # SPDX-License-Identifier: MPL-2.0
 cd "$SRC"/echidna
 cargo +nightly fuzz build
+# `fuzz` is excluded from the workspace (`Cargo.toml:154-157`), so
+# cargo-fuzz writes artefacts into the fuzz crate's own target dir
+# (`fuzz/target/<TRIPLE>/release/`) rather than the workspace
+# `./target/`. cp from the correct path or every iteration of the
+# loop fails with `cp: cannot stat …/target/x86_64-…/release/<bin>`
+# and bash -eu exits on the first miss (echidna#143).
 for target in $(cargo +nightly fuzz list); do
-    cp ./target/x86_64-unknown-linux-gnu/release/$target $OUT/
+    cp ./fuzz/target/x86_64-unknown-linux-gnu/release/$target $OUT/
 done