Add --enforce mode to enroll diff and add --ignore-package-versions

If there is diff detected between the two harvests, and it can
enforce restoring the state from the older harvest, it will
manifest the state and apply it with ansible. Only the specific
roles that had diffed will be applied (via the new tags capability).

`--ignore-package-versions` will skip reporting when packages are
upgraded/downgraded in the diff.

README.md

@@ -108,6 +108,17 @@ Generate Ansible output from an existing harvest bundle.
 **Common flags**
 - `--fqdn <host>`: enables **multi-site** output style
 
+**Role tags**
+Generated playbooks tag each role so you can target just the parts you need:
+
+- Tag format: `role_<role_name>` (e.g. `role_services`, `role_users`)
+- Fallback/safe tag: `role_other`
+
+Example:
+```bash
+ansible-playbook -i "localhost," -c local /tmp/enroll-ansible/playbook.yml --tags role_services,role_users
+```
+
 ---
 
 ### `enroll single-shot`
@@ -131,7 +142,26 @@ Compare two harvest bundles and report what changed.
 **Inputs**
 - `--old <harvest>` and `--new <harvest>` (directories or `state.json` paths)
 - `--sops` when comparing SOPS-encrypted harvest bundles
-- `--exclude-path` if you want to ignore certain files that changed in the diff
+- `--exclude-path <PATTERN>` (repeatable) to ignore file/dir drift under matching paths (same pattern syntax as harvest)
+- `--ignore-package-versions` to ignore package version-only drift (upgrades/downgrades)
+- `--enforce` to apply the **old** harvest state locally (requires `ansible-playbook` on `PATH`)
+
+**Noise suppression**
+- `--exclude-path` is useful for things that change often but you still want in the harvest baseline (e.g. `/var/anacron`).
+- `--ignore-package-versions` keeps routine upgrades from alerting; package add/remove drift is still reported.
+
+**Enforcement (`--enforce`)**
+If a diff exists and `ansible-playbook` is available, Enroll will:
+1) generate a manifest from the **old** harvest into a temporary directory
+2) run `ansible-playbook -i localhost, -c local <tmp>/playbook.yml` (often with `--tags role_<...>` to limit runtime)
+3) record in the diff report that the old harvest was enforced
+
+Enforcement is intentionally “safe”:
+- reinstalls packages that were removed (`state: present`), but does **not** attempt downgrades/pinning
+- restores users, files (contents + permissions/ownership), and service enable/start state
+
+If `ansible-playbook` is not on `PATH`, Enroll returns an error and does not enforce.
+
 
 **Output formats**
 - `--format json` (default for webhooks)
@@ -417,6 +447,16 @@ enroll diff   --old /path/to/golden/harvest   --new /path/to/new/harvest   --web
 enroll diff --old /path/to/harvestA --new /path/to/harvestB --exclude-path /var/anacron
 ```
 
+### Ignore package version drift (routine upgrades) but still alert on add/remove
+```bash
+enroll diff --old /path/to/harvestA --new /path/to/harvestB --ignore-package-versions
+```
+
+### Enforce the old harvest state when drift is detected (requires Ansible)
+```bash
+enroll diff --old /path/to/harvestA --new /path/to/harvestB --enforce --ignore-package-versions --exclude-path /var/anacron
+```
+
 ---
 
 ## Explain
@@ -492,6 +532,12 @@ ansible-playbook -i "localhost," -c local /tmp/enroll-ansible/playbook.yml
 ansible-playbook /tmp/enroll-ansible/playbooks/"$(hostname -f)".yml
 ```
 
+### Run only specific roles (tags)
+Generated playbooks tag each role as `role_<name>` (e.g. `role_users`, `role_services`), so you can speed up targeted runs:
+```bash
+ansible-playbook -i "localhost," -c local /tmp/enroll-ansible/playbook.yml --tags role_users
+```
+
 ## Configuration file
 
 As can be seen above, there are a lot of powerful 'permutations' available to all four subcommands.
@@ -541,6 +587,12 @@ exclude_path = /usr/local/bin/docker-*, /usr/local/bin/some-tool
 no_jinjaturtle = true
 sops = 00AE817C24A10C2540461A9C1D7CDE0234DB458D
 
+[diff]
+# ignore noisy drift
+exclude_path = /var/anacron
+ignore_package_versions = true
+# enforce = true  # requires ansible-playbook on PATH
+
 [single-shot]
 # if you use single-shot, put its defaults here.
 # It does not inherit those of the subsections above, so you