Complete Phase 3, Phase 5 polish and hardening

Phase 3 — Investments:
- Multi-currency support: holdings track purchase currency, FX rates convert to base for totals
- Capital gains report using UK Section 104 pool method, grouped by tax year
- Capital Gains tab added to Reports page

Phase 5 — Polish & Hardening:
- Mobile-responsive layout: bottom nav, sidebar hidden on mobile, logo in TopBar, compact header buttons, hover-only actions now always visible on touch
- Backup system: encrypted GPG backups via backup.sh, nightly scheduler job, admin API (list/trigger/download/restore), Settings UI with drag-to-restore confirmation
- Docker entrypoint with gosu privilege drop to fix bind-mount ownership on fresh deployments
- OWASP fixes: refresh token now bound to its session (new refresh_token_hash column + migration), CSRF secure flag tied to environment, IP-level rate limiting on login, TOTPEnableRequest Pydantic schema replaces raw dict
- AES-256-GCM key rotation script (rotate_keys.py) with dry-run mode and atomic DB transaction
- CLAUDE.md added for AI-assisted development context
- README updated: correct reverse proxy port, accurate backup/restore commands, key rotation instructions

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/app/api/v1/transactions.py

@@ -48,6 +48,7 @@ async def get_transactions(
     date_from: str | None = None,
     date_to: str | None = None,
     search: str | None = None,
+    is_recurring: bool | None = None,
     page: int = Query(default=1, ge=1),
     page_size: int = Query(default=50, ge=1, le=200),
     db: AsyncSession = Depends(get_db),
@@ -62,6 +63,7 @@ async def get_transactions(
         date_from=date.fromisoformat(date_from) if date_from else None,
         date_to=date.fromisoformat(date_to) if date_to else None,
         search=search,
+        is_recurring=is_recurring,
         page=page,
         page_size=page_size,
     )