Initial scaffold: generation-rule-only Crossplane Bucket example

Educational RunWhen CodeCollection that discovers Crossplane GCP
Bucket CRDs (storage.gcp.upbound.io/v1beta1) and generates one SLX
per bucket. Ships only generation rules and Jinja templates; the
runtime lives in rw-generic-codecollection/k8s-kubectl-cmd (already
loaded by the airgap runner).

Includes:
- codebundles/gcp-bucket-crossplane-health with generation rule + 3 templates
- docs/01..07 numbered training chapters with screenshot placeholders
- README, .gitignore

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

docs/01-overview.md

@@ -0,0 +1,75 @@
+# 01 — Overview
+
+## What you'll do in this guide
+
+By the end of this guide you will have a private RunWhen CodeCollection that:
+
+1. Is hosted in your Gitea instance (already the case for this workspace —
+   see `https://gitea.airgap.shared.runwhen.com/gitea-admin/simple-private-codecollection`).
+2. **Contains no Robot Framework code of its own.** It only ships two things:
+   - **Generation rules** — YAML that tells RunWhen's workspace-builder
+     which resources to discover in the cluster and how many SLXs to
+     generate for each match.
+   - **Templates** — Jinja files that render the `ServiceLevelX`,
+     `ServiceLevelIndicator`, and `Runbook` resources for each match.
+3. Reuses an existing generic codebundle — `k8s-kubectl-cmd` from
+   [`rw-generic-codecollection`](https://github.com/runwhen-contrib/rw-generic-codecollection/tree/main/codebundles/k8s-kubectl-cmd) —
+   as the runtime for every generated SLI and TaskSet.
+4. Discovers **Crossplane GCP Bucket** custom resources
+   (`buckets.storage.gcp.upbound.io/v1beta1`) and produces one SLX per
+   Bucket with a fractional health SLI and a detailed condition-based
+   TaskSet.
+
+## Vocabulary primer
+
+| Term | Meaning |
+|------|---------|
+| **CodeCollection** | A Git repository, cloned by RunWhen, that contains one or more codebundles. This repo is a CodeCollection. |
+| **CodeBundle** | A subdirectory of a CodeCollection (`codebundles/<name>/`). Traditionally contains Robot Framework code plus discovery rules. **Ours contains only discovery rules and templates.** |
+| **Generation rule** | YAML under `.runwhen/generation-rules/`. Declares which resource types to scan and how to build SLXs from matches. |
+| **Template** | Jinja YAML under `.runwhen/templates/`. Rendered per matching resource by workspace-builder to produce the final SLX / SLI / Runbook artifacts. |
+| **SLX** | A "Service Level X" — the top-level unit of monitoring in RunWhen. Bundles together an SLI, an optional SLO, and one or more Runbooks. |
+| **SLI** | Service Level Indicator — a numeric health signal (here `0.0` to `1.0`) pushed on an interval. |
+| **Runbook / TaskSet** | The interactive troubleshooting sequence. Called a "Runbook" in `kind`, "TaskSet" in the UI. |
+| **workspace-builder** | The pod (image `runwhen-local`) that clones code collections, indexes resources, matches generation rules, renders templates, and uploads the resulting workspace to the platform. |
+
+## The pattern in one diagram
+
+![overview diagram](images/01-overview-diagram.png)
+
+*(Placeholder — replace with a screenshot exported from your diagramming
+tool once the flow is verified end-to-end.)*
+
+```mermaid
+flowchart LR
+  Private["Gitea<br/>simple-private-codecollection<br/>(rules + templates)"]
+  WB["workspace-builder<br/>(clones + indexes + renders)"]
+  Cluster[("GKE cluster<br/>Crossplane Bucket CRDs")]
+  Generic["rw-generic-codecollection<br/>k8s-kubectl-cmd<br/>(sli.robot + runbook.robot)"]
+
+  Private --> WB
+  Cluster --> WB
+  WB -->|"one SLX per Bucket"| Platform["RunWhen Platform"]
+  Platform -->|"Runner pulls robots from"| Generic
+  Generic -->|kubectl + jq| Cluster
+```
+
+## When to use this pattern
+
+Choose the "generation-rule only" pattern when:
+
+- You want to **discover organization-specific resources** (CRDs, tags,
+  labels) without maintaining a fork of the shared code collections.
+- The **runtime already exists** as a generic bundle
+  (`k8s-kubectl-cmd`, `curl-cmd`, `gcloud-cmd`, `aws-cmd`, etc.) and you
+  just need to point it at the right target.
+- You want changes to your discovery rules to land **without a codebundle
+  runner image rebuild** — workspace-builder re-clones on each reconcile.
+
+Do NOT use it when you need custom Robot keywords, a task that
+can't be expressed as a single `kubectl`/`gcloud`/`curl` command, or a
+runtime that isn't already available in a generic bundle.
+
+## Next
+
+Continue to [02 — Generation-rule-only pattern](02-generation-rules-only-pattern.md).