docs(ai): fix Claude 4.x model name order to match ModelType.ts

[MukundaKatta]

Fixes #8573.

The AI-kit models page listed 4.x Claude variants as Claude <VERSION> <SIZE> (e.g. Claude 4.5 Haiku) while amplify-data's ModelType.ts only accepts Claude <SIZE> <VERSION> for 4+ (Claude Haiku 4.5, Claude Sonnet 4.5, …) — matching Bedrock's own naming change for post-Claude-4 models. Copying the name from the docs into a.ai.model(...) produced a TS compile error because the string wasn't a keyof typeof supportedModelsLookup.

Fixed all 5 table rows on src/pages/[platform]/ai/concepts/models/index.mdx:

- <TableCell>Claude 4.5 Haiku</TableCell>
+ <TableCell>Claude Haiku 4.5</TableCell>

- <TableCell>Claude 4.5 Sonnet</TableCell>
+ <TableCell>Claude Sonnet 4.5</TableCell>

- <TableCell>Claude 4.5 Opus</TableCell>
+ <TableCell>Claude Opus 4.5</TableCell>

- <TableCell>Claude 4.6 Sonnet</TableCell>
+ <TableCell>Claude Sonnet 4.6</TableCell>

- <TableCell>Claude 4.6 Opus</TableCell>
+ <TableCell>Claude Opus 4.6</TableCell>

3.x rows are unchanged (they correctly use Claude 3.5 Haiku/Claude 3.5 Sonnet, matching ModelType.ts). Docs-only change.