- Platform::contentOverflow returns int (0 = fits) via max(), drops the
nullable-int + ternary pattern; HasSocialHttpClient and the validation
rule updated to compare against 0 instead of null.
- Drop the hardcoded 63206-char limit to 10000 across all entry points
(Platform enum, MCP CreatePostTool/UpdatePostTool, FacebookRules, all
three FormRequests). Facebook's API accepts up to 63206 but nobody
writes 63k-char posts and emoji-heavy content risks overflowing the
TEXT column's 65535-byte ceiling.
- Compiled i18n JSON regenerated with the content_exceeds_platform key.
Threads posts over 500 chars were saved + scheduled successfully and only
failed inside the publish job. The frontend already showed the 537|500 badge
but `canSchedule` ignored content length, so Schedule and Post Now stayed
enabled. Backend `UpdatePostRequest` only capped at 63206 (Facebook's max),
not per-platform.
- Add `Platform::contentOverflow()` as the single source of truth and reuse it
from `HasSocialHttpClient::validateContentLength` (publish-time).
- New `ContentFitsPlatformLimits` rule applied to the `content` field on
`App\\UpdatePostRequest`, `Api\\UpdatePostRequest`, and `Api\\StorePostRequest`
via `Rule::when(...)` so drafts are not blocked.
- Rule dedupes per platform (two Threads accounts -> one error) and reports
the platform label, hard cap, and overage via i18n.
- Edit.vue feeds `contentLengthOverflows` into `canSchedule` and lists each
offending platform in `postActionTooltip` using the existing
`getPlatformLabel` resolver.
