Allow larger autocorrect dictionaries via configurable link size

[MustafaNisar2002]

Description

This PR relaxes the size limit on autocorrect dictionaries so tables larger than 64KB can be generated and used safely.

• Allow the autocorrect runtime to read tries with either 2- or 3-byte node links, using AUTOCORRECT_LINK_BYTE_COUNT defined in the generated header.
• Update the autocorrect data generator to compute entry sizes, try 2-byte links first, and automatically switch to 3-byte links when the serialized table would exceed 64KB.
• Emit AUTOCORRECT_LINK_BYTE_COUNT in generated autocorrect_data.h files and annotate the default autocorrect dictionary with its link size.
• Document the new link format behaviour in docs/features/autocorrect.md.

Types of Changes

• [x] Core
• [x] Enhancement/optimization
• [x] Documentation

Issues Fixed or Closed by This PR

• Fixes qmk/qmk_firmware#25823

Checklist

• [x] My code follows the code style of this project: C, Python
• [x] I have read the PR Checklist document and have made the appropriate changes.
• [x] My change requires a change to the documentation.
• [x] I have updated the documentation accordingly.
• [x] I have added tests or basic checks to cover my changes (e.g. python -m compileall lib/python/qmk/cli/generate/autocorrect_data.py and firmware builds with a generated dictionary).
• [x] I have tested the changes and verified that they work and don't break anything (as well as I can manage).