Regenerate docs, update CHANGELOG for v1.0.0, clean up registry manifest

- Regenerated docs/ via tfplugindocs: 51 files covering all 20 resources
  and 30 data sources with auto-extracted schemas and examples
- Removed stale docs for old resources (build.md, ssh.md)
- CHANGELOG.md: added v1.0.0 entry with full feature list, breaking
  changes, and security notes
- terraform-registry-manifest.json: confirmed protocol_versions ["6.0"]
  is correct for Terraform Plugin Framework

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/data-sources/ssh_keys_by_user.md

@@ -0,0 +1,39 @@
+---
+# generated by https://github.com/hashicorp/terraform-plugin-docs
+page_title: "virtfusion_ssh_keys_by_user Data Source - virtfusion"
+subcategory: ""
+description: |-
+  Fetches all SSH keys for a VirtFusion user.
+---
+
+# virtfusion_ssh_keys_by_user (Data Source)
+
+Fetches all SSH keys for a VirtFusion user.
+
+
+
+<!-- schema generated by tfplugindocs -->
+## Schema
+
+### Required
+
+- `user_id` (Number) The user ID to fetch SSH keys for.
+
+### Optional
+
+- `results` (Number) Maximum number of results to return. Defaults to 300.
+
+### Read-Only
+
+- `ssh_keys` (Attributes List) List of SSH keys belonging to the user. (see [below for nested schema](#nestedatt--ssh_keys))
+
+<a id="nestedatt--ssh_keys"></a>
+### Nested Schema for `ssh_keys`
+
+Read-Only:
+
+- `enabled` (Boolean) Whether the SSH key is enabled.
+- `id` (Number) The SSH key ID.
+- `name` (String) The SSH key name.
+- `public_key` (String) The public key content.
+- `type` (String) The SSH key type.