Implements core Grafana dashboard generation using Go structs:
- Dashboard struct with UID, Title, Tags, Links, Rows, Templating
- Panel types: timeseries, stat, gauge, text, table
- Automatic gridPos calculation and panel ID assignment
- Gap annotation support for missing metrics
- Threshold configuration for gauges
- Uses datasource UID PBFA97CFB590B2093 (Prometheus)

All tests passing (11 test cases).

User request: Create a Go package that generates Grafana dashboard JSON 
from Go structs to avoid hand-writing verbose JSON and make dashboards 
maintainable and testable.

Note: Code partially generated by AI (Claude Sonnet 4.5)

Creates generate/main.go with:
- writeJSON helper for writing dashboard JSON files
- main() with configurable output directory
- Placeholder for dashboard generation (to be added in Tasks 2-6)

CLI builds successfully and is ready for dashboard definitions.

User request: Create CLI entrypoint that imports dashboard definitions 
and writes JSON files.

Note: Code partially generated by AI (Claude Sonnet 4.5)

Implements Task 2: Level 1 — Service Map Dashboard (StackRox Overview)

This commit adds the top-level overview dashboard for the StackRox monitoring
hierarchy. The dashboard provides a service map view with three main sections:

- Service Health: Central process metrics (up status, CPU, memory, goroutines, version)
- Connected Sensors: Cluster connectivity metrics (sensors, clusters, nodes, vCPUs)
- Database: PostgreSQL health metrics (connection status, size, active connections, available space)

The dashboard includes a drill-down link to the Level 2 'Central Internals' dashboard
for detailed component analysis.

Implementation follows test-driven development methodology with comprehensive test
coverage verifying dashboard structure, panel configuration, and JSON validity.

Files:
- deploy/charts/monitoring/dashboards/generator/l1_overview.go: Dashboard definition
- deploy/charts/monitoring/dashboards/generator/l1_overview_test.go: Test suite
- deploy/charts/monitoring/dashboards/generator/generate/main.go: CLI integration

User request: Implement Task 2: Level 1 — Service Map Dashboard following TDD methodology.
Dashboard uses existing metrics from Central service (standard Go runtime metrics and
custom StackRox metrics for sensor connectivity and database health).

Note: Code partially generated with AI assistance (Claude Sonnet 4.5).

Implements the Level 2 dashboard that displays a grid view of all 10 logical
regions within Central. Each region includes headline metrics and a link to
its corresponding Level 3 detail dashboard.

Dashboard structure:
- UID: central-internals
- 10 rows (one per logical region): Sensor Ingestion, Deployment Processing,
  Vulnerability Enrichment, Detection & Alerts, Risk Calculation, Background
  Reprocessing, Pruning & GC, Network Analysis, Report Generation, API & UI
- Each row contains 3-4 metric panels plus a details link to Level 3
- Back-link to Level 1 StackRox Overview dashboard

Notable features:
- Identifies existing metrics gaps with text panels (e.g., no alert generation
  rate metric, no Central-side report generation metrics)
- Uses histogram_quantile for p95 latency calculations
- Uses rate() for counter metrics to show per-second rates
- Follows StackRox dashboard generator patterns and testing conventions

Testing:
- Comprehensive test coverage in l2_central_test.go
- All 16 tests pass
- Validates metadata, row structure, panel queries, and JSON generation

CLI integration:
- Added L2 dashboard generation to generate/main.go
- Outputs central-internals.json alongside stackrox-overview.json

Implemented using TDD methodology: tests written first, then implementation,
following Go best practices and StackRox coding style.

User request: Implement Task 3: Level 2 — Central Internals Dashboard

Code partially generated with AI assistance (Claude Code).

Implement the highest-value Level 3 detail dashboard for Central's Sensor
Ingestion pipeline with comprehensive metrics breakdowns.

Dashboard structure (central-sensor-ingestion):
- Connection Status: sensor connectivity and state transitions
- Deduper: throughput, hit rate, hash store size, and operations
- Worker Queue: event processing, duration, with gap annotations for
  missing queue depth and in-flight metrics
- Pipeline Processing: resource processing, panics, K8s event latency,
  with gap annotation for per-fragment metrics
- Messages Not Sent: failed sends to sensor with type and reason

Key features:
- 3 gap annotation panels identify missing observability metrics
- Full metric breakdowns with proper legend formats
- Links back to Level 2 Central Internals dashboard
- Follows TDD: comprehensive test coverage for all rows and panels

Generated files:
- deploy/charts/monitoring/dashboards/central-sensor-ingestion.json

Task: ROX-33737 Phase 0 - Dashboard Hierarchy Prototype

Partially AI-assisted.

Implements Task 5 from the Central metrics dashboard project.

This dashboard provides deep visibility into the vulnerability enrichment
pipeline with comprehensive metrics for:
- Scan semaphore utilization and queue management
- Image scanning performance (p50/p95/p99 latencies)
- Node scanning metrics
- Image deduplication statistics
- Registry client requests, latency, and timeout tracking

Includes 2 gap annotations identifying missing metrics:
- Enrichment request counter (for failure rate calculation)
- Node scan counter

Test-driven development: comprehensive test suite covering all rows,
panels, queries, and JSON generation.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Implements Task 6: Create stub dashboards for the 8 remaining logical regions
in Central. Each dashboard has real panels where metrics exist and prominent
gap annotations documenting missing metrics.

Dashboard UIDs:
- central-deployment-processing: Deployment/pod/namespace resource processing
- central-detection-alerts: Detection engine and alert generation
- central-risk-calculation: Risk scoring and reprocessing
- central-background-reprocessing: Background loops and batch processing
- central-pruning-gc: Process pruning and garbage collection
- central-network-analysis: Network flows and endpoint tracking
- central-report-generation: Compliance operator and vuln reports
- central-api-ui: GraphQL, gRPC, and API endpoint metrics

All dashboards:
- Include level-3 tag and back-link to central-internals dashboard
- Mix real metric panels (timeseries/stat) with gap annotation panels
- Document needed metrics for complete observability

Implementation follows TDD methodology:
1. Wrote comprehensive tests first (l3_stubs_test.go)
2. Implemented L3Stubs() function with 8 dashboard specs
3. Integrated into CLI generator (generate/main.go)
4. Verified all tests pass and JSON output is valid

Files:
- Created: deploy/charts/monitoring/dashboards/generator/l3_stubs.go
- Created: deploy/charts/monitoring/dashboards/generator/l3_stubs_test.go
- Modified: deploy/charts/monitoring/dashboards/generator/generate/main.go

Test results: All 77 tests pass.

AI-assisted implementation based on user specification.

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