refactor(agentos): establish bundle-first agent-native runtime

[siwei-yuan]

Summary

• keep PocketJS as the single JavaScript substrate with one resident Pi Agent System Guest and independent three-entry View and Action Guest LRUs
• extract the pure-JavaScript Pocket Pi System Framework and enforce App = Data + Actions + View with actor-neutral Actions and SQLite-backed Projection
• migrate Exa and Robinhood to the shared Action contract and rename the package descriptor directly from agent-app.json to app.json
• keep native code focused on hardware, isolation, security enforcement, bounded lifecycle, create-only install, and uninstall
• remove the old data-action artifacts and do not retain compatibility shims or App replacement semantics

Validation

• cargo fmt --all --check
• cargo test --workspace: 41 passed
• Exa and Robinhood App builds and pocketapp packaging passed; archive contents use app.json only
• ESP32-P4 release Firmware build passed
• git diff --check passed

Explicit non-goals

• raw JavaScript source-module loading or on-device JSX transformation
• independent System Framework or System App updates
• App replacement, upgrade, rollback, dependency graphs, or a second JavaScript runtime