docs(typedef): sync specs with ADRs 099-102 (19 kinds, aligned-mode restrictions, read factory)
- schema-layer.md: 17→19 kinds, add Int64/Uint64 to table + TypeDefKind
enum, update method tables (12 fixed-size kinds, 8-byte alignment for
i64/u64/f64), add ADR-099 to design decisions.
- layout-engine.md: document ADR-100 (non-final inline variable field
rejection), ADR-102 (TUnion rejected in aligned mode), ADR-101
(sequential_reader returns owned reader). Update TUnion section to
note aligned-mode rejection. Add ADRs to design decisions table.
- data-access.md: add I64/U64 to FieldValue enum, update
sequential_reader() signature (factory, ADR-101).
- validation.md: 17→19 kinds, update TypedefEngine struct (no stored
reader in Layout::Packed), update sequential_reader() signature.
- overview.md: 17→19 kinds, add ADRs 099-102 to design decisions.
- README.md (typedef): 17→19 kinds, add ADRs 099-102 to applicable ADRs.
- README.md (top-level): add ADRs 099-102 to ADR table, update typedef
doc descriptions (17→19 kinds).
glm-5.2
a5d5d037dd