refactor: enforce strict linting and type checking across codebase

- Expand ruff rules (B, S, SIM, RET, COM, C4, G, PT, PIE, T20, DTZ, ICN, TCH, RUF, ANN)
- Switch pyright to strict mode with relaxed test environment
- Replace try-except-pass with contextlib.suppress throughout
- Move type-only imports into TYPE_CHECKING blocks
- Replace ambiguous Unicode chars (en dash, multiplication sign, Greek alpha) with ASCII
- Move color-matcher from base deps to [gpu], remove unused requests dep
- Add pyright to dev deps, update dependabot to uv ecosystem
- Fix hardcoded version in test_version, unused unpacked vars in tests
- Update maintain.sh, CLAUDE.md, .gitignore, .claude/settings.json
- Remove obsolete .agents/rules/project.md
- Upgrade all dependencies (Pygments vulnerability fix)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/test_humanizer.py

@@ -8,7 +8,7 @@ def test_humanizer_does_not_modify_original_if_disabled():
     img[50, 50] = [100, 150, 200]
     org_img = img.copy()
 
-    # grain=0, shift=0 means disabled essentially. But wait, apply_analog_humanizer currently applies chromatic shift even if grain=0.
+    # grain=0, shift=0 means disabled — result should match original.
     result = apply_analog_humanizer(img, grain_intensity=0.0, chromatic_shift=0)
     assert np.array_equal(result, org_img)