Adopt generated reader assets and retain only maintained client documentation #136

Upgrade Flutter/CI to 3.47.9, pin the reader revision that generates its web worker automatically, and use native UTC calendar boundaries for consistent date-key equality. Remove implementation reports/screenshots and redundant product snapshots; preserve install, release and Windows verification guides with uppercase Markdown names.

Dependency: PapyrusReader/reader#22.

Acceptance: committed reader Git pin and lock agree without local overrides; analysis, tests and web/native builds pass; surviving documentation links resolve. Maintenance work; no release version bump.