Character library and four-founder migration

The new starting roster is Moss, Pip, Pebble and Ember. Legacy IDs remain stable; the old prototype has a private pre-migration checkpoint and retired founder memories remain outside resident observations and exports. Active family obligations are preserved. Native character collection and ZIP chooser code is in place, backed by bounded self-contained GLB validation and immutable model versions. Measured on 14 October 2026: 39 importer tests passed in 2.44 seconds (tests/test_character_packs.py); 22 isolated API tests passed in 2.07 seconds (character-api-source-4ea6ebc0aebd); 64 simulation/vision tests passed in 1.97 seconds. These scopes overlap and are not summed into a project total. The four 384 x 384 Unity portrait renders below are the first camera iteration: they exposed a rear-view orientation that needs correction. Original build/camera metadata is retained. Final native UI and imported-avatar motion remain pending.