changelog: PCD-9784 documentation

Author: PF9-pushkar

CHANGELOG.md

@@ -4,6 +4,29 @@ All notable changes to this project are documented here. The format is based on
 [Keep a Changelog](https://keepachangelog.com/en/1.1.0/), and this project adheres to
 [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Documentation
+
+- **Every import now says where its ID comes from** (PCD-9784). Each resource's Import section
+  names the `pcdctl` command (or resource-manager call) that prints the ID it needs, and a new
+  [Importing guide](docs/guides/importing.md) covers CLI setup, `terraform import` versus
+  `import` blocks with generated configuration, a per-resource lookup table, the resmgr host
+  UUID, and a worked blueprint import.
+- **A runnable Community Edition example** at `examples/complete/community-edition/`, rendered
+  by the new [Community Edition guide](docs/guides/community-edition.md): from one prepared
+  host to a running instance with an NFS-backed volume attached, in one apply. Validated end to
+  end on a Community Edition 2026.4 lab.
+- `pcd_blockstorage_volume_type` and `pcd_cluster_blueprint` explain how `volume_backend_name`,
+  `storage_backends_json`, `image_library_storage`, and `pcd_host_cluster_role.backends` fit
+  together; the README's PCD-native table adds `pcd_cluster` and `pcd_host_cluster_role`.
+- **Corrected `pcd_host_cluster_role.backends`:** it lists the *second-level* keys of
+  `storage_backends_json` (the driver configuration names), not the top-level backend names as
+  the description said. The top-level key is what becomes `volume_backend_name` on the host.
+  Naming a top-level key in `backends` yields an empty backend set, `cinder-volume` cannot
+  start, and the host is stuck converging while resmgr refuses every role change (409). The
+  mistake was invisible while every example used the same name at both levels.
+
 ## [0.1.10] - 2026-09-03
 
 ### Changed