Fix HIGH priority issues: unbounded queries, rate limiting, health checks

Issue #3 - Unbounded Query Results (OOM):
- get_all_archived_history() now uses keyset pagination with bounded max_rows (50k default)
- Added 'id' field to records from get_archived_history() and get_archived_history_keyset()
- Protocol signature updated with page_size, max_rows, last_ban_id params

Issue #7 - Docker Health Check Fails:
- Added curl to Dockerfile.backend runtime image
- HEALTHCHECK now uses 'curl -f http://localhost:8000/api/health'
- compose.prod.yml: increased start_period to 40s, timeout to 10s
- Frontend healthcheck proxies to backend /api/health

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

backend/app/mappers/blocklist_mappers.py

@@ -0,0 +1,141 @@
+"""Blocklist response mappers.
+
+Convert domain models (from blocklist_service) to response models (for HTTP API).
+
+This is the mapping layer at the router boundary, ensuring the service layer
+remains independent of HTTP response shapes.
+"""
+
+from __future__ import annotations
+
+from app.models.blocklist import (
+    BlocklistSource,
+    ImportLogEntry,
+    ImportLogListResponse,
+    ImportRunResult,
+    ImportSourceResult,
+    PreviewResponse,
+    ScheduleConfig,
+    ScheduleFrequency,
+    ScheduleInfo,
+)
+from app.models.blocklist_domain import (
+    DomainBlocklistSource,
+    DomainImportLogEntry,
+    DomainImportLogList,
+    DomainImportRunResult,
+    DomainImportSourceResult,
+    DomainPreviewResult,
+    DomainScheduleConfig,
+    DomainScheduleFrequency,
+    DomainScheduleInfo,
+)
+from app.utils.pagination import create_pagination_metadata
+
+
+def map_domain_blocklist_source_to_response(
+    domain: DomainBlocklistSource,
+) -> BlocklistSource:
+    """Convert domain blocklist source to response model."""
+    return BlocklistSource(
+        id=domain.id,
+        name=domain.name,
+        url=domain.url,
+        enabled=domain.enabled,
+        created_at=domain.created_at,
+        updated_at=domain.updated_at,
+    )
+
+
+def map_domain_import_log_entry_to_response(
+    domain: DomainImportLogEntry,
+) -> ImportLogEntry:
+    """Convert domain import log entry to response model."""
+    return ImportLogEntry(
+        id=domain.id,
+        source_id=domain.source_id,
+        source_url=domain.source_url,
+        timestamp=domain.timestamp,
+        ips_imported=domain.ips_imported,
+        ips_skipped=domain.ips_skipped,
+        errors=domain.errors,
+    )
+
+
+def map_domain_import_log_list_to_response(
+    domain_list: DomainImportLogList,
+) -> ImportLogListResponse:
+    """Convert domain import log list to response model."""
+    return ImportLogListResponse(
+        items=[map_domain_import_log_entry_to_response(i) for i in domain_list.items],
+        pagination=create_pagination_metadata(
+            domain_list.total, domain_list.page, domain_list.page_size
+        ),
+    )
+
+
+def map_domain_schedule_frequency_to_response(
+    domain: DomainScheduleFrequency,
+) -> ScheduleFrequency:
+    """Convert domain schedule frequency to response model."""
+    return ScheduleFrequency(domain.value)
+
+
+def map_domain_schedule_config_to_response(
+    domain: DomainScheduleConfig,
+) -> ScheduleConfig:
+    """Convert domain schedule config to response model."""
+    return ScheduleConfig(
+        frequency=map_domain_schedule_frequency_to_response(domain.frequency),
+        interval_hours=domain.interval_hours,
+        hour=domain.hour,
+        minute=domain.minute,
+        day_of_week=domain.day_of_week,
+    )
+
+
+def map_domain_schedule_info_to_response(domain: DomainScheduleInfo) -> ScheduleInfo:
+    """Convert domain schedule info to response model."""
+    return ScheduleInfo(
+        config=map_domain_schedule_config_to_response(domain.config),
+        next_run_at=domain.next_run_at,
+        last_run_at=domain.last_run_at,
+        last_run_errors=domain.last_run_errors,
+    )
+
+
+def map_domain_preview_result_to_response(domain: DomainPreviewResult) -> PreviewResponse:
+    """Convert domain preview result to response model."""
+    return PreviewResponse(
+        entries=domain.entries,
+        total_lines=domain.total_lines,
+        valid_count=domain.valid_count,
+        skipped_count=domain.skipped_count,
+    )
+
+
+def map_domain_import_source_result_to_response(
+    domain: DomainImportSourceResult,
+) -> ImportSourceResult:
+    """Convert domain import source result to response model."""
+    return ImportSourceResult(
+        source_id=domain.source_id,
+        source_url=domain.source_url,
+        ips_imported=domain.ips_imported,
+        ips_skipped=domain.ips_skipped,
+        error=domain.error,
+    )
+
+
+def map_domain_import_run_result_to_response(
+    domain: DomainImportRunResult,
+) -> ImportRunResult:
+    """Convert domain import run result to response model."""
+    return ImportRunResult(
+        results=[
+            map_domain_import_source_result_to_response(r) for r in domain.results
+        ],
+        total_imported=domain.total_imported,
+        total_skipped=domain.total_skipped,
+        errors_count=domain.errors_count,
+    )