feat(bf-3xl3t): verify cargo fuzz build for profile_yaml

- Executed cargo fuzz build profile_yaml successfully
- Binary built at fuzz/target/x86_64-unknown-linux-gnu/release/profile_yaml (58MB)
- No errors or warnings during build
- Build completed without hangs or delays

Closes bf-3xl3t

notes/bf-3xl3t.md

@@ -0,0 +1,47 @@
+# bf-3xl3t: Execute cargo fuzz build for profile_yaml
+
+## Execution Summary
+
+**Command:** `cargo fuzz build profile_yaml`
+**Status:** ✅ SUCCESS
+**Build Time:** ~10-15 seconds (no explicit timing captured, but completed quickly)
+**Output Size:** 58MB binary
+
+## Build Artifacts
+
+- **Binary:** `fuzz/target/x86_64-unknown-linux-gnu/release/profile_yaml`
+- **Timestamp:** July 6, 2026 15:19
+- **Size:** 58M
+
+## Verification
+
+```bash
+$ cargo fuzz --version
+cargo-fuzz 0.13.1
+
+$ cargo fuzz list
+cmap_parser
+content
+lexer
+object_parser
+profile_yaml
+stream_decoder
+xref
+
+$ cargo fuzz build profile_yaml
+# No output = success
+
+$ ls -lh fuzz/target/x86_64-unknown-linux-gnu/release/profile_yaml
+-rwxr-xr-x 2 coding users 58M Jul  6 15:19 fuzz/target/x86_64-unknown-linux-gnu/release/profile_yaml
+```
+
+## Notes
+
+- The build completed without errors or warnings
+- No hangs or excessive delays observed
+- The profile_yaml harness is now ready for fuzzing
+- Previous beads verified the cargo-fuzz installation (bf-dcyku) and source code structure (bf-4zhtc)
+
+## Parent Bead Status
+
+This bead (bf-3xl3t) completes the build verification step. Parent bead bf-4c49w (cargo fuzz build verification) can now proceed.