docs: align container COSI filenames with pipeline behavior

The pipeline storm-trident helper prepare-images renames all COSI images
to the same output filenames regardless of runtime. Align the manual build
instructions to match so Host Configuration image URLs work unchanged for
both runtimes.

Also:
- Add explicit SSH public key injection step (configs ship with empty
  sshPublicKeys list, which blocks pytest SSH access)
- Restructure Host Configuration section with subheadings for clarity

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: bfjelds

docs/Development/Testing/E2E-Tests.md

@@ -60,9 +60,14 @@ Trident RPMs).
 
 | Image | Output File | Bootloader | Integrity | Configurations |
 |-------|------------|-----------|-----------|----------------|
-| `trident-container-testimage` | `container.cosi` | grub2 | None | base, encrypted-partition, encrypted-raid, encrypted-swap, extensions, health-checks-install, misc, raid-mirrored, raid-resync-small, raid-small, simple |
-| `trident-container-verity-testimage` | `container-verity.cosi` | grub2 | Root dm-verity | root-verity |
-| `trident-container-usrverity-testimage` | `container-usrverity.cosi` | systemd-boot | `/usr` dm-verity (UKI) | combined, rerun, usr-verity, usr-verity-raid |
+| `trident-container-testimage` | `regular.cosi` | grub2 | None | base, encrypted-partition, encrypted-raid, encrypted-swap, extensions, health-checks-install, misc, raid-mirrored, raid-resync-small, raid-small, simple |
+| `trident-container-verity-testimage` | `verity.cosi` | grub2 | Root dm-verity | root-verity |
+| `trident-container-usrverity-testimage` | `usrverity.cosi` | systemd-boot | `/usr` dm-verity (UKI) | combined, rerun, usr-verity, usr-verity-raid |
+
+Container images use the **same output filenames** as their host counterparts
+(`regular.cosi`, `verity.cosi`, `usrverity.cosi`). This matches the pipeline's
+`storm-trident helper prepare-images` behavior and means Host Configuration
+image URLs work unchanged for both runtimes.
 
 Container test images do **not** include Trident RPMs — Trident runs from a
 Docker container (`trident-container.tar.gz`) loaded at runtime. The images
@@ -207,28 +212,30 @@ mv artifacts/test-image/trident-usrverity-testimage_1.cosi artifacts/test-image/
 #### Container Runtime Images
 
 Container images include Docker and a `trident-container.service` but omit
-Trident RPMs — Trident runs from the container tarball instead:
+Trident RPMs — Trident runs from the container tarball instead. Rename the
+output files to match the host image filenames so Host Configuration image
+URLs work unchanged:
 
 ```bash
 mkdir -p artifacts/test-image
 
 # Regular container image
 sudo ./tests/images/testimages.py build trident-container-testimage \
     --output-dir ./artifacts/test-image --clones 2
-mv artifacts/test-image/trident-container-testimage_0.cosi artifacts/test-image/container.cosi
-mv artifacts/test-image/trident-container-testimage_1.cosi artifacts/test-image/container_v2.cosi
+mv artifacts/test-image/trident-container-testimage_0.cosi artifacts/test-image/regular.cosi
+mv artifacts/test-image/trident-container-testimage_1.cosi artifacts/test-image/regular_v2.cosi
 
 # Verity container image (for root-verity configuration)
 sudo ./tests/images/testimages.py build trident-container-verity-testimage \
     --output-dir ./artifacts/test-image --clones 2
-mv artifacts/test-image/trident-container-verity-testimage_0.cosi artifacts/test-image/container-verity.cosi
-mv artifacts/test-image/trident-container-verity-testimage_1.cosi artifacts/test-image/container-verity_v2.cosi
+mv artifacts/test-image/trident-container-verity-testimage_0.cosi artifacts/test-image/verity.cosi
+mv artifacts/test-image/trident-container-verity-testimage_1.cosi artifacts/test-image/verity_v2.cosi
 
 # UKI/usr-verity container image (for usr-verity, combined configurations)
 sudo ./tests/images/testimages.py build trident-container-usrverity-testimage \
     --output-dir ./artifacts/test-image --clones 2
-mv artifacts/test-image/trident-container-usrverity-testimage_0.cosi artifacts/test-image/container-usrverity.cosi
-mv artifacts/test-image/trident-container-usrverity-testimage_1.cosi artifacts/test-image/container-usrverity_v2.cosi
+mv artifacts/test-image/trident-container-usrverity-testimage_0.cosi artifacts/test-image/usrverity.cosi
+mv artifacts/test-image/trident-container-usrverity-testimage_1.cosi artifacts/test-image/usrverity_v2.cosi
 ```
 
 The images use the Image Customizer container from
@@ -286,8 +293,7 @@ make starter-configuration
 ```
 
 This copies `tests/e2e_tests/trident_configurations/simple/trident-config.yaml`
-to `input/trident.yaml`. Edit it to add your SSH public key under
-`os.users[0].sshPublicKeys`.
+to `input/trident.yaml`.
 
 Alternatively, copy a configuration directly from any test configuration
 directory:
@@ -297,16 +303,39 @@ mkdir -p input
 cp tests/e2e_tests/trident_configurations/<config>/trident-config.yaml input/trident.yaml
 ```
 
+#### Add your SSH public key
+
+The test configurations ship with an empty `sshPublicKeys` list. Add your
+public key so pytest can SSH into the VM after install:
+
+```yaml
+os:
+  users:
+    - name: testing-user
+      sshPublicKeys:
+        - <contents of artifacts/id_rsa.pub>
+      sshMode: key-only
+```
+
+:::tip
+If you generated keys with `make artifacts/id_rsa`, paste the contents of
+`artifacts/id_rsa.pub` into the list.
+:::
+
+#### Image URLs
+
 The Host Configuration references image URLs like
 `http://NETLAUNCH_HOST_ADDRESS/files/regular.cosi`. Netlaunch automatically
 replaces `NETLAUNCH_HOST_ADDRESS` with its own `<host-IP>:<port>` at runtime,
 so the VM can reach the files served by netlaunch.
 
-:::note Container runtime Host Configuration
+Because both host and container COSI images are renamed to the same output
+filenames (see [Build COSI Images](#8-build-cosi-images)), the image URLs in
+the Host Configuration work unchanged for both runtimes.
+
+:::note Container runtime — additional configuration
 For the **container** runtime, the Host Configuration must include an
-`additionalFiles` entry to copy the Trident container tarball onto the VM.
-Storm-trident and the pipeline's `edit_host_config.py` add this automatically
-when `--runtimeEnv container` is specified:
+`additionalFiles` entry to copy the Trident container tarball onto the VM:
 
 ```yaml
 os:
@@ -315,8 +344,8 @@ os:
       destination: /var/lib/trident/trident-container.tar.gz
 ```
 
-If running manually with the container runtime, add this entry to your Host
-Configuration.
+Storm-trident and the pipeline's `edit_host_config.py` add this automatically
+when `--runtimeEnv container` is specified. It is only needed for manual runs.
 :::
 
 ### 3. Run netlaunch