Polish: trademark disclaimer, CI on push, GitHub Pages docs, unit tests

[KillDaWill]

• README: badges, How it works section, trademark disclaimer, fixed Downloading A Release typo, fixed _ escape, split macOS into Apple Silicon and Intel, --mode clarification, Contributing.
• THIRD_PARTY_NOTICES: explicit Trademarks section.
• source/pokemon_catalog.c: header comment clarifying the strings are Nintendo/Game Freak/Creatures Inc. trademarks.
• LICENSE: copyright to KillDaWill.
• Makefile: removed print debug target, added make test target, doxygen now reads docs/Doxyfile, release-clean updated.
• Doxyfile -> docs/Doxyfile; output under docs/build/.
• .gitignore: collapsed docs/html, docs/latex, doxygen-warnings into /docs/build/.
• .github/workflows/ci.yml: Linux + Windows build + make test on push to main and on every PR.
• .github/workflows/docs.yml: Doxygen -> GitHub Pages on push.
• .github/workflows/release.yml: macos-x86_64 matrix entry with -arch x86_64 build step.
• .github/ISSUE_TEMPLATE: bug_report and feature_request templates.
• CHANGELOG.md: 1.0.0 entry plus an Unreleased entry.
• tests/: zero-dep harness with 16 tests covering LZ10 detection, passthrough, back-reference, and roundtrips; pokemon_catalog count, sequencing, spot-checks, and out-of-range lookups.