snap: add revision parameter (#11984)

* feat(snap): add ``revision`` parameter

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* feat(snap): add changelog fragment for PR 11984

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/integration/targets/snap/tasks/main.yml

@@ -19,5 +19,7 @@
       ansible.builtin.include_tasks: test_dangerous.yml
     - name: Include test_3dash
       ansible.builtin.include_tasks: test_3dash.yml
+    - name: Include test_revision
+      ansible.builtin.include_tasks: test_revision.yml
     - name: Include test_empty_list
       ansible.builtin.include_tasks: test_empty_list.yml

tests/integration/targets/snap/tasks/test_revision.yml

@@ -0,0 +1,60 @@
+---
+# Copyright (c) Ansible Project
+# GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+- name: Make sure package is not installed (uhttpd)
+  community.general.snap:
+    name: uhttpd
+    state: absent
+
+- name: Install package at specific revision (uhttpd rev 15)
+  community.general.snap:
+    name: uhttpd
+    state: present
+    revision: 15
+  register: install_revision
+
+- name: Install same revision again - idempotency (uhttpd rev 15)
+  community.general.snap:
+    name: uhttpd
+    state: present
+    revision: 15
+  register: install_revision_again
+
+- name: Assert revision install behavior
+  assert:
+    that:
+      - install_revision is changed
+      - install_revision_again is not changed
+
+- name: Install different revision (uhttpd rev 45)
+  community.general.snap:
+    name: uhttpd
+    state: present
+    revision: 45
+  register: install_different_revision
+
+- name: Assert switching to a different revision triggers change
+  assert:
+    that:
+      - install_different_revision is changed
+
+- name: Remove package (uhttpd)
+  community.general.snap:
+    name: uhttpd
+    state: absent
+
+- name: Verify channel and revision are mutually exclusive
+  community.general.snap:
+    name: uhttpd
+    state: present
+    channel: latest/stable
+    revision: 15
+  register: install_channel_and_revision
+  ignore_errors: true
+
+- name: Assert channel and revision are mutually exclusive
+  assert:
+    that:
+      - install_channel_and_revision is failed