# pdftract-1sxpa: BI/ID inline image header parser

## Summary

Implemented the BI/ID inline image header parser that parses the header between `BI` and `ID` keywords in PDF inline images. The parser handles:

- Shorthand key expansion per ISO 32000-1 Table 92 (e.g., `/W` -> `/Width`)
- Key-value pair parsing with support for all direct object types
- Array filter chains (e.g., `/F [/ASCII85Decode /FlateDecode]`)
- ID whitespace validation (must be followed by exactly one whitespace byte)
- Malformed header recovery (byte-by-byte scanning for next `/Key` or `ID`)

## Files Modified

- `crates/pdftract-core/src/parser/inline_image.rs`
  - Implemented `recover_to_next_key` function (was TODO stub)
  - Fixed test assertion: `StructInvalidDictValue` -> `StructInvalidType`
  - Fixed ID whitespace validation test input
- `crates/pdftract-core/src/markdown.rs`
  - Fixed test calls to include `tables` parameter
- `tests/fixtures/profiles/PROVENANCE.md`
  - Added book_chapter fixture provenance entries

## Acceptance Criteria

- **PASS**: `BI /W 10 /H 10 /CS /DeviceGray /BPC 8 /F /ASCIIHexDecode ID ...EI` parses successfully
  - Test: `test_parse_basic_header`
- **PASS**: Shorthand expansion (`/W` -> `/Width`) yields `header.width == 10`
  - Test: `test_shorthand_expansion` + `test_parse_basic_header`
- **PASS**: Array filter `/F [/ASCII85Decode /FlateDecode]` parses
  - Test: `test_parse_header_with_array_filter`
- **PASS**: ID without trailing whitespace emits diagnostic
  - Test: `test_id_whitespace_validation` (emits `InlineImageIdWhitespaceMissing`)
- **PASS**: Malformed header (missing value) emits diagnostic and recovers
  - Test: `test_parse_header_with_missing_value` (emits `StructInvalidType`)

## Test Results

All 14 inline_image tests pass:
```
PASS [   0.007s] parser::inline_image::tests::test_scan_inline_image_data_empty
PASS [   0.008s] parser::inline_image::tests::test_scan_inline_image_data_lexer_position
PASS [   0.008s] parser::inline_image::tests::test_parse_basic_header
PASS [   0.008s] parser::inline_image::tests::test_inline_image_header_new
PASS [   0.008s] parser::inline_image::tests::test_scan_inline_image_data_basic
PASS [   0.008s] parser::inline_image::tests::test_id_whitespace_validation
PASS [   0.009s] parser::inline_image::tests::test_parse_header_with_array_filter
PASS [   0.009s] parser::inline_image::tests::test_inline_image_header_has_required_fields
PASS [   0.009s] parser::inline_image::tests::test_scan_inline_image_data_binary_content
PASS [   0.009s] parser::inline_image::tests::test_scan_inline_image_data_no_ei
PASS [   0.010s] parser::inline_image::tests::test_scan_inline_image_data_various_whitespace
PASS [   0.011s] parser::inline_image::tests::test_parse_header_with_missing_value
PASS [   0.004s] parser::inline_image::tests::test_scan_inline_image_data_with_embedded_ei
PASS [   0.004s] parser::inline_image::tests::test_shorthand_expansion
```

## Commit

- Hash: `4ac8479`
- Message: `test(pdftract-1sxpa): complete inline image header parser implementation`

## References

- Plan section: Phase 3.5 Parsing paragraph (line 1596)
- ISO 32000-1 sec 8.9.7, Table 92