Add Python RFC 5322 email address parser (§3.2-§4.4) with 70 tests and compliance matrix

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Summary

Implements RFC 5322 compliant email address parser as specified in issue #1 — full ABNF grammar coverage from §3.2 through §4.4 with strict and permissive modes.

Files added

File	Lines	Description
parser.py	750+	AddressParser class with parse(), parse_address_list(), parse_mailbox_list()
test_parser.py	480+	70 test cases across 10 test classes organized by RFC section
compliance.md	107	Maps all 51 ABNF productions to RFC sections, test cases, and implementation status

Modified files

File	Change	Description
source.md	2 CAP blocks	Contribution Annotation Protocol blocks (§3.2.1-§3.2.5 and §3.4 areas)

Acceptance criteria

• parser.py — AddressParser class with parse(), parse_address_list(), parse_mailbox_list() | ✓
• Strict mode rejects all obs-* productions; permissive mode accepts them | ✓ (70 tests)
• Quoted-string handling implements full §3.2.4 (quoted-pair, FWS within quotes) | ✓
• CFWS correctly handled: stripped from addr-spec, comments extracted and stored | ✓
• Domain literals support both IPv4 and IPv6 forms per §3.4.1 | ✓
• Group addresses correctly parsed with member list extraction | ✓
• test_parser.py — 60+ test cases covering all sections listed above | ✓ (70 tests)
• compliance.md — maps all ABNF productions to tests and implementation | ✓ (51 productions)
• All [CAP-ANNOTATION-REQUIRED] markers in source.md populated per CONTRIBUTING.md | ✓ (2 blocks)
• No external dependencies — pure Python stdlib only | ✓
• Type hints on all public methods | ✓
• Parser handles inputs up to 998 characters (RFC 5322 line length limit) | ✓

Test results

============================== 70 passed in 0.08s ==============================

Test coverage by section

Section	Tests	Status
§3.2.1 quoted-pair	5	✓
§3.2.2 FWS	5	✓
§3.2.3 CFWS/comments	8	✓
§3.2.4 quoted-string	8	✓
§3.2.5 miscellaneous tokens	3	✓
§3.4 address/mailbox/group	12	✓
§3.4.1 addr-spec/domain-literal	8	✓
§4.4 obsolete addressing	8	✓
Edge cases	5	✓
Invalid/rejection	8	✓

Architecture

parser.py
├── RFC5322Address (dataclass) — parsed result
├── RFC5322Lexer — §3.2 lexical analysis (quoted-pair, FWS, CFWS, quoted-string, atoms)
└── AddressParser — recursive descent parser for §3.4 address productions
    ├── parse()          — single mailbox/group
    ├── parse_address_list() — comma-separated addresses
    └── parse_mailbox_list() — comma-separated mailboxes (rejects groups)

Co-Authored-By: Nebula noreply@nebula.gg