docs: align quick start with source framing

[dapi]

Summary

• describe Feature Flow as a specification-driven vertical slice in both READMEs and the daily usage guide
• clarify that the agent executes Memory Bank routing
• describe the GIFs as interaction scenarios rather than input-only demonstrations
• render every terminal GIF on an exact 120-column Menlo grid with 24 px text and 1.5 times more visible rows
• remove manual line wrapping from prompts that fit within the 120-column grid
• add the routing GIF to the Russian README

Verification

• git diff --check
• ruby tools/validate-priming-manifests.rb template/memory-bank
• memory-bank-cli lint --scope-root template/memory-bank --entrypoint template/memory-bank/README.md
• memory-bank-cli doctor --profile template
• shellcheck publishing/production/scripts/build-memory-bank-quick-start-gifs.sh in the private corp-content source workspace
• deterministic GIF rerender
• visual inspection of every GIF frame at README display scale
• verified 120 columns and no prompt longer than 106 characters
• frame-count and dimension inspection for all three GIFs