Feat/e2e remote badge delete

[AdWav]

Summary

• Fix log/history retrieval to query by resolved user_id only instead of mixing badge_id and user_id filters.
• Add defensive early returns when badge-to-user resolution fails (None or -1) to avoid invalid queries.
• Reorganize README documentation headings to separate global documentation notes from E2E documentation.
• Update docs/DATABASE.md to align database documentation with the E2E deletion/synchronization workflow.
• Add explicit server/client table mapping for E2E validation (event_type, event_log_sync, *_sync, *_write), plus SQL verification guidance tied to E2E logs.

Why

• The query changes prevent inconsistent history results caused by mixed identity filters and make behavior safer when user resolution fails.
• The README update improves navigation between general project documentation and E2E-specific procedures.
• The database documentation now better reflects the real end-to-end deletion lifecycle (soft/hard delete, event import, and processing state), improving traceability and debugging.

Test Plan

• Run E2E tests.
• Validate user info lookup and 5-last-logs behavior with a valid badge.
• Validate behavior with an unknown badge (no crash, empty data returned).
• Manually verify README section structure renders correctly.
• Review docs/DATABASE.md and cross-check E2E table/event semantics against tests/E2E/README.md.
• Confirm documented SQL checks match snapshots in tests/E2E/logs/E2E_logs.txt.