fix(bf-2zdma): restore content fuzz harness and verify build

- Restore fuzz/fuzz_targets/content.rs from commit b05a90c6
- File was missing from current tree but defined in Cargo.toml
- Verify cargo fuzz build content completes successfully
- Add verification note at notes/bf-2zdma.md

Acceptance criteria:
- cargo fuzz build content completes successfully: PASS
- No compilation errors or warnings: PASS
- fuzz/target directory exists and contains build artifacts: PASS
- All fuzz dependencies are resolved: PASS

Closes bf-2zdma

fuzz/fuzz_targets/content.rs

@@ -0,0 +1,22 @@
+//! Fuzz target for the PDF content stream interpreter.
+//!
+//! This target tests INV-8 (no panic at public boundary) for the content stream interpreter.
+//! Any panic indicates a content stream bug that must be fixed.
+
+#![no_main]
+use libfuzzer_sys::fuzz_target;
+
+fuzz_target!(|data: &[u8]| {
+    use pdftract_core::content_stream::{process_with_mode, ProcessingMode};
+    use pdftract_core::parser::resources::ResourceDict;
+
+    // The content stream interpreter must never panic on any input
+    // Create a minimal empty resource dict for testing
+    let resources = ResourceDict::new();
+
+    // Test in Normal mode
+    let _ = process_with_mode(data, &resources, ProcessingMode::Normal, None);
+
+    // Test in PositionHint mode
+    let _ = process_with_mode(data, &resources, ProcessingMode::PositionHint, None);
+});

notes/bf-2zdma.md

@@ -0,0 +1,39 @@
+# Verification: bf-2zdma - Verify fuzz harness builds without errors
+
+## Date
+2026-07-05
+
+## Task
+Verify that the content fuzz harness compiles successfully and all dependencies are properly configured.
+
+## Findings
+
+### Issue Discovered
+The `content.rs` fuzz target was defined in `fuzz/Cargo.toml` but the source file `fuzz/fuzz_targets/content.rs` was missing from the current tree. The file existed in commit `b05a90c6` ("chore: add fuzz harness content parser") but was not present in the current working tree or HEAD.
+
+### Resolution
+Restored `fuzz/fuzz_targets/content.rs` from commit `b05a90c6`. The file contains:
+- Fuzz target for PDF content stream interpreter
+- Tests INV-8 (no panic at public boundary)
+- Tests both `ProcessingMode::Normal` and `ProcessingMode::PositionHint`
+
+### Build Verification
+- Command: `cargo fuzz build content`
+- Result: **SUCCESS** - no compilation errors or warnings
+- Build artifact: `fuzz/target/x86_64-unknown-linux-gnu/release/content` (56.5 MB)
+- Build timestamp: 2026-07-05 17:26
+
+### Acceptance Criteria Status
+| Criterion | Status |
+|-----------|--------|
+| `cargo fuzz build content` completes successfully | ✅ PASS |
+| No compilation errors or warnings | ✅ PASS |
+| fuzz/target directory exists and contains build artifacts | ✅ PASS |
+| All fuzz dependencies are resolved | ✅ PASS |
+
+## Artifacts Created
+- Restored: `fuzz/fuzz_targets/content.rs`
+- Build artifact: `fuzz/target/x86_64-unknown-linux-gnu/release/content`
+
+## Conclusion
+The fuzz harness builds successfully. The missing `content.rs` file was restored from git history. All acceptance criteria are **PASS**.