docs: restructure documentation and move scripts to scripts/

- Add docs/ hierarchy: guides, backends, operations, reference, design
- Slim root README; add documentation index and links to docs/
- Add missing docs: csv-format-flexibility, dns-resolution, dtail-metrics-example, magefile
- Document Prometheus/VictoriaMetrics and ClickHouse backends
- Move all helper shell scripts to scripts/; update Magefile and doc references
- Add ASCII diagrams for watch mode (CSV watcher), auto mode, and ingestion paths
- Add .gitignore

Co-authored-by: Cursor <cursoragent@cursor.com>

1 files changed, 66 insertions, 0 deletions

diff --git a/docs/reference/example-queries.md b/docs/reference/example-queries.md
new file mode 100644
index 0000000..e78aaec
--- /dev/null
+++ b/docs/reference/example-queries.md
@@ -0,0 +1,66 @@
+# Example Queries
+
+PromQL and curl examples for Epimetheus test metrics. Use your Prometheus (or Prometheus-compatible) query URL; after port-forward, that is often http://localhost:9090.
+
+## Basic PromQL
+
+```promql
+# Total requests
+epimetheus_test_requests_total
+
+# Request rate (last 5 minutes)
+rate(epimetheus_test_requests_total[5m])
+
+# Active connections
+epimetheus_test_active_connections
+
+# Temperature
+epimetheus_test_temperature_celsius
+```
+
+## Histogram
+
+```promql
+# 95th percentile request duration
+histogram_quantile(0.95, rate(epimetheus_test_request_duration_seconds_bucket[5m]))
+
+# Median (50th percentile)
+histogram_quantile(0.50, rate(epimetheus_test_request_duration_seconds_bucket[5m]))
+
+# Average request duration
+rate(epimetheus_test_request_duration_seconds_sum[5m]) /
+rate(epimetheus_test_request_duration_seconds_count[5m])
+```
+
+## Labeled counter
+
+```promql
+# Failed jobs by type
+epimetheus_test_jobs_processed_total{status="failed"}
+
+# Job success rate
+rate(epimetheus_test_jobs_processed_total{status="success"}[5m]) /
+rate(epimetheus_test_jobs_processed_total[5m])
+
+# Total jobs by type
+sum by (job_type) (epimetheus_test_jobs_processed_total)
+```
+
+## Curl (HTTP API)
+
+```bash
+# Port-forward if needed
+kubectl port-forward -n monitoring svc/prometheus-kube-prometheus-prometheus 9090:9090 &
+
+# Total requests
+curl -s "http://localhost:9090/api/v1/query?query=epimetheus_test_requests_total" | jq .
+
+# Temperature
+curl -s "http://localhost:9090/api/v1/query?query=epimetheus_test_temperature_celsius" | jq .
+
+# Request rate
+curl -s "http://localhost:9090/api/v1/query?query=rate(epimetheus_test_requests_total[5m])" | jq .
+
+# Histogram p95
+curl -s "http://localhost:9090/api/v1/query?query=histogram_quantile(0.95,rate(epimetheus_test_request_duration_seconds_bucket[5m]))" | jq .
+```