[sebxt]

typescript_property_aware_rename only quoted names containing -. A field renamed with serde to something like @type, schema.org or 2fa was written bare and the generated interface failed to parse.

This change quotes the name whenever it is not a plain identifier: the first character must be a letter, _ or $, and the rest letters, digits, _ or $. Names that were valid before are emitted unchanged, and - names are still quoted, so existing snapshots do not change.

Changes:

• core/src/language/typescript.rs: identifier check in typescript_property_aware_rename.
• New TypeScript snapshot test can_quote_non_identifier_field_names covering @type, schema.org, 2fa and $ref (which stays unquoted).

Testing:

• cargo test -p typeshare-core --test snapshot_tests passes; the new test fails without the generator change.
• tsc --noEmit (TypeScript 5.6.3) reports 5 syntax errors on the old output and none on the new one.

Fixes #299