test: backfill raw/global/computed report triplet coverage across plugins

The bats coverage for plugin :report keys has been uneven since the raw/global/computed split landed in PR #8640. This commit adds a single combined triplet test per settable property across app-json, builder, builder-dockerfile, builder-herokuish, builder-lambda, builder-nixpacks, builder-pack, builder-railpack, buildpacks, cron (maintenance), git (keep-git-dir, rev-env-var, source-image), logs (vector-sink, vector-global-image, vector-global-networks), network (attach-post-create, attach-post-deploy, initial-network), proxy (per-app type), ps (stop-timeout-seconds), registry (image-repo, push-on-release, push-extra-tags), storage (build/deploy/run mounts), and adds a new tests/unit/scheduler.bats and tests/unit/nginx-vhosts_properties.bats. Brings ps `procfile-path` and `stop-timeout-seconds` global getters in line with the #8640 convention (raw global, default resolved in computed). Documents the read-only and internal properties that surface in `:report` (or are written by Dokku) but cannot be managed by `:set` in a new `## Internal properties` section appended to each affected plugin's docs page.

docs/networking/proxies/caddy.md

@@ -265,3 +265,11 @@ You can pass flags which will output only the value of the specific information
 ```shell
 dokku caddy:report node-js-app --caddy-computed-image
 ```
+
+## Internal properties
+
+The following properties are not managed by `caddy:set` but are recorded internally by the plugin:
+
+| Property | Kind | Description | Source |
+|---|---|---|---|
+| `proxy-status` | internal | `started`/`stopped` state of the caddy compose project | `cmd-caddy-start`/`cmd-caddy-stop` in `plugins/caddy-vhosts/command-functions` |

docs/networking/proxies/haproxy.md

@@ -244,3 +244,11 @@ You can pass flags which will output only the value of the specific information
 ```shell
 dokku haproxy:report node-js-app --haproxy-computed-image
 ```
+
+## Internal properties
+
+The following properties are not managed by `haproxy:set` but are recorded internally by the plugin:
+
+| Property | Kind | Description | Source |
+|---|---|---|---|
+| `proxy-status` | internal | `started`/`stopped` state of the haproxy compose project | `cmd-haproxy-start`/`cmd-haproxy-stop` in `plugins/haproxy-vhosts/command-functions` |

docs/networking/proxies/nginx.md

@@ -620,3 +620,13 @@ See the [ports documentation](/docs/networking/port-management.md) for more info
 ### Regenerating nginx config
 
 See the [proxy documentation](/docs/networking/proxy-management.md#regenerating-proxy-config) for more information on how to rebuild the nginx proxy configuration for your app.
+
+## Internal properties
+
+The following properties surface in `nginx:report` but are not managed by `nginx:set`, or are recorded internally by the plugin:
+
+| Property | Kind | Description | Source |
+|---|---|---|---|
+| `--nginx-last-visited-at` | read-only | UNIX timestamp of the last request served by nginx for the app | log-tailer writes the property on every request batch |
+| `proxy-status` | internal | `started`/`stopped` state of the nginx system service | `cmd-nginx-start`/`cmd-nginx-stop` |
+| `nginx-conf-sigil-migrated` | internal | Migration sentinel set the first time a v1 template is rewritten to the current schema | `plugins/nginx-vhosts/install` writes `"true"` once the install-time migration runs |

docs/networking/proxies/traefik.md

@@ -390,3 +390,11 @@ You can pass flags which will output only the value of the specific information
 ```shell
 dokku traefik:report node-js-app --traefik-computed-api-enabled
 ```
+
+## Internal properties
+
+The following properties are not managed by `traefik:set` but are recorded internally by the plugin:
+
+| Property | Kind | Description | Source |
+|---|---|---|---|
+| `proxy-status` | internal | `started`/`stopped` state of the traefik compose project | `cmd-traefik-start`/`cmd-traefik-stop` in `plugins/traefik-vhosts/command-functions` |