docs(bf-21yde): verify cargo-fuzz installation and fuzzing prerequisites

Add verification note confirming:
- cargo-fuzz 0.13.1 installed and functional
- fuzz/ directory structure complete with all required files
- 'content' fuzz target properly defined in Cargo.toml
- rust-fuzzer toolchain components installed
- All 7 fuzz targets available (cmap_parser, content, lexer, object_parser, profile_yaml, stream_decoder, xref)

Closes bf-21yde

notes/bf-21yde.md

@@ -0,0 +1,61 @@
+# cargo-fuzz Installation Verification (bf-21yde)
+
+Date: 2026-07-06
+
+## Verification Summary
+
+All cargo-fuzz prerequisites are verified and functional.
+
+## Checklist Results
+
+### 1. cargo-fuzz installation
+- **Status:** PASS
+- `cargo fuzz --version` outputs: `cargo-fuzz 0.13.1`
+- No errors encountered
+
+### 2. fuzz/ directory structure
+- **Status:** PASS
+- Directory exists at `/home/coding/pdftract/fuzz/`
+- Contains required files:
+  - `fuzz/Cargo.toml` (with `cargo-fuzz = true` metadata)
+  - `fuzz/Cargo.lock`
+  - `fuzz/fuzz_targets/` directory (7 harness files)
+  - `fuzz/corpus/` directory
+  - `fuzz/target/` directory
+
+### 3. 'content' target definition
+- **Status:** PASS
+- Defined in `fuzz/Cargo.toml` at lines 40-41:
+  ```toml
+  [[bin]]
+  name = "content"
+  path = "fuzz_targets/content.rs"
+  ```
+- Actual file exists: `fuzz/fuzz_targets/content.rs` (822 bytes)
+
+### 4. Toolchain availability
+- **Status:** PASS
+- `rustup` shows multiple installed toolchains (stable, nightly, versioned)
+- Required components installed:
+  - `llvm-tools-x86_64-unknown-linux-gnu`
+  - `rust-std-x86_64-unknown-linux-gnu`
+  - `rustc-x86_64-unknown-linux-gnu`
+
+## Available Fuzz Targets
+
+`cargo fuzz list` shows all 7 configured targets:
+- cmap_parser
+- content
+- lexer
+- object_parser
+- profile_yaml
+- stream_decoder
+- xref
+
+## Conclusion
+
+All acceptance criteria met. No errors about missing cargo-fuzz or toolchain components. The fuzzing infrastructure is ready for use.
+
+## Commit Work
+
+This verification note will be committed as the work product for this bead.