framework/lib/path.test.ts    |  22 ++
 framework/lib/path.ts         |   5 +-
 lib/Lru.test.ts               |  22 ++
 lib/Lru.ts                    |   4 +
 lib/http.test.ts              | 133 +++++++
 lib/http.ts                   |  32 +-
 lib/readme.changes.md         |   9 +
 src/file-viewer/backend.ts    |  24 +-
 src/file-viewer/cache.test.ts | 603 +++++++++++++++++++++++++++++
 src/file-viewer/cache.ts      | 661 +++++++++++++++-----------------
 src/source-of-truth.test.ts   |  51 +++
 src/source-of-truth.ts        |  14 +-
 12 files changed, 1201 insertions(+), 379 deletions(-)