)

* feat: add block-level LWW for fine-grained text conflict resolution

Implements block-level Last-Writer-Wins for text columns across SQLite
and PostgreSQL. Text is split into blocks (lines by default) and each
block is tracked independently, so concurrent edits to different parts
of the same text are preserved after sync.

- Add block.c/block.h with split, diff, position, and materialize logic
- Add fractional-indexing submodule for stable block ordering
- Add cloudsync_set_column() and cloudsync_text_materialize() functions
- Add cross-platform SQL abstractions for blocks table (SQLite/PostgreSQL)
- Add block handling to PG insert, update, col_value, and set_column
- Move network code to src/network/ directory
- Bump version to 0.9.200
- Add 36 SQLite block LWW unit tests and 7 PostgreSQL test files
- Update README and API docs with block-level LWW documentation

* fix(ci): checkout submodules in GitHub Actions workflow

…previous release