chore(release): CHANGELOG for #79/#81 + ignore qlever submodule build dirt

[Haigutus]

Release prep for the next pre-release (0.2.0a2 pending version decision). No source/behavior changes.

• CHANGELOG — adds the two entries missing after the recent merges:
  • fix(sparql): qlever accepts bare pyarrow input like the other engines #79 (Fixed): qlever accepts a bare pyarrow Table/RecordBatch input, like the other engines.
  • rdfs_tools: derive class attributes from schema:domainIncludes as well as rdfs:domain #81 (Changed): the RDFS→JSON schema generator reads schema:domainIncludes as well as rdfs:domain, and emits attributes with no class binding as top-level entries (with a warning) instead of dropping them.
    (feat(validation): sh:ValidationReport export, locate/context passes, sequence paths #80 brought its own entries; docs: N-Quads export is 552-edition-independent #78 was docs-only.)
• .gitmodules — ignore = dirty on vendor/qlever so the local qlever build/test index files (LibQlever.buildIndexFromInjectedParser.index.*) stop showing as a superproject change. Pinned commit unchanged.

The examples/ run artifacts (*.ttl, *.sarif, entsoe_shacl/) were already gitignored by #80 — no change needed.