feat(mutator): rewrite generator on @gramio/schema-parser, bump to 0.7.0

Replaces the old tg-bot-api/custom.min.json pipeline with @gramio/schema-parser's
getCustomSchema(). The generator walks method parameters recursively, tracking
union/optional path segments, collects transforms, dedupes them, then renders
two shapes: direct mutation for non-array paths, `.map()` + spread for array
paths. The emitted code uses an `isFormattableString` helper so nested
`input_message_content.message_text` narrows cleanly across union variants.

Regenerated src/mutator.ts for Telegram Bot API 9.6 — now covers 32 methods
including sendMessageDraft, sendPaidMedia, sendPoll.description, sendChecklist,
and editMessageChecklist. Also bumps @gramio/types to 9.6.0.

A small post-load fallback patches InputTextMessageContent.message_text for
@gramio/schema-parser < 1.1.0; upstream fix lives in schema-parser@1.1.0.