Whole-project `flutter analyze` exited 1 on 17 pre-existing info/warning
lints (no errors) in dev tools and test files. Clean them so analyze is
green:
- editor_repository_test: drop the redundant sqflite_common import; keep
the used utils import with a transitive-dep ignore.
- pen_* widget tests: `(_, __)` wildcard params -> `(_, _)`.
- search_snippet_test / gen_bench_pdf / gen_dense_strokes: drop needless
interpolation braces; remove an unused `Size` show and an unused local;
mark the gen tool as print-allowed.
No runtime behavior changed. flutter analyze: No issues found. Affected
tests: 22/22 pass.
A stylus point drawn at 2x zoom maps to the correct normalized page coordinate
(canvas-local 200,300 → scene 100,150 → normalized 0.25,0.25), guarding that ink
stays glued to the page under zoom/pan — the core own-canvas invariant.
flutter analyze lib/editor clean; 238/238 tests (+1).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>