docs(pdftract-5dng): add verification note for name object lexer

The PDF name object lexer was already fully implemented with
all acceptance criteria passing. Added verification note documenting
test results.

Co-Authored-By: Claude Code <noreply@anthropic.com>
Bead-Id: pdftract-5dng

notes/pdftract-5dng.md

@@ -0,0 +1,80 @@
+# pdftract-5dng: PDF Name Object Lexer Implementation
+
+## Summary
+
+The PDF name object lexer was already fully implemented in `crates/pdftract-core/src/parser/lexer/mod.rs` (lines 658-767). All acceptance criteria pass with comprehensive test coverage.
+
+## Acceptance Criteria Status
+
+### PASS
+
+All critical tests from the plan pass:
+
+1. **`/Foo` -> `Token::Name(b"Foo")`** - `name_simple` test
+2. **`/Foo#20Bar` -> `Token::Name(b"Foo Bar")`** - `name_with_hex_escape_space` test (#20 = space)
+3. **`/Foo#00Bar` -> `Token::Name(b"Foo")` + `STRUCT_INVALID_NAME`** - `name_nul_byte_rejected` test
+4. **`/AAA...AAA` (128 A's) -> `Token::Name(b"AAA...AAA")` (127 A's) + `STRUCT_INVALID_NAME`** - `name_length_limit_127_bytes` test
+5. **`/` (alone) -> `Token::Name(b"")` (no diagnostic)** - `name_empty` test
+6. **`/#23#23` -> `Token::Name(b"##")`** - `name_hex_escape_decodes_to_hash` test (#23 = #)
+7. **`/Foo#GZ` -> `Token::Name(b"Foo#GZ")` + `STRUCT_INVALID_NAME`** - `name_invalid_hex_escape_keeps_hash_literal` test
+
+### Proptests
+
+- **`name_proptest_never_panics_on_random_bytes`** - PASS
+- **`name_proptest_always_produces_valid_token`** - PASS
+
+### INV-8
+
+The implementation maintains INV-8 (lexer invariant). The name lexer properly:
+- Tracks raw byte consumption (`raw_consumed`)
+- Enforces 127-byte raw length limit before hex expansion
+- Rejects NUL bytes (0x00) with `STRUCT_INVALID_NAME` diagnostic
+- Truncates at 127 raw bytes, avoiding half-decoded escapes
+
+## Implementation Details
+
+The `lex_name()` function:
+
+1. **Entry**: Position immediately after the leading `/`
+2. **Hex escapes (`#XX`)**: Decodes to single byte, checking for valid hex digits
+3. **NUL rejection**: Detects both literal NUL and `#00` escape, emits diagnostic, truncates at NUL
+4. **Length limit**: 127 raw bytes (before hex expansion), truncates cleanly before incomplete `#XX` sequences
+5. **Termination**: Stops at whitespace or any PDF delimiter
+6. **Empty name**: `/` followed by delimiter/EOF produces `Token::Name(b"")` with no diagnostic
+
+## Test Results
+
+```
+running 23 tests
+test parser::lexer::tests::name_case_sensitive ... ok
+test parser::lexer::tests::name_hex_escape_decodes_to_hash ... ok
+test parser::lexer::tests::name_empty ... ok
+test parser::lexer::tests::name_hex_escape_zero_zero_is_nul ... ok
+test parser::lexer::tests::name_invalid_hex_escape_keeps_hash_literal ... ok
+test parser::lexer::tests::name_invalid_hex_escape_single_digit ... ok
+test parser::lexer::tests::name_empty_followed_by_delimiter ... ok
+test parser::lexer::tests::name_length_limit_127_bytes ... ok
+test parser::lexer::tests::name_length_limit_exact_127_bytes_valid ... ok
+test parser::lexer::tests::name_hex_escape_mixed_case ... ok
+test parser::lexer::tests::name_simple ... ok
+test parser::lexer::tests::name_nul_byte_rejected ... ok
+test parser::lexer::tests::name_length_limit_counts_raw_bytes_before_expansion ... ok
+test parser::lexer::tests::name_multiple_invalid_hex_escapes ... ok
+test parser::lexer::tests::name_literal_nul_byte_rejected ... ok
+test parser::lexer::tests::name_truncation_before_incomplete_escape ... ok
+test parser::lexer::tests::name_with_bytes_preserved ... ok
+test parser::lexer::tests::name_with_all_delimiters ... ok
+test parser::lexer::tests::name_with_hex_escape_space ... ok
+test parser::lexer::tests::name_with_slash_delimiter ... ok
+test parser::lexer::tests::name_zero_byte_not_confused_with_nul ... ok
+test parser::lexer::tests::name_proptest_never_panics_on_random_bytes ... ok
+test parser::lexer::tests::name_proptest_always_produces_valid_token ... ok
+
+test result: ok. 23 passed; 0 failed; 0 ignored
+```
+
+Full lexer suite: 77 tests passed.
+
+## Files Modified
+
+No changes required - implementation was already complete.