ci: add snap publishing workflow

This commit adds snap publishing and promotion to the CI process.

For nightly releases, upload the built snaps to the 'latest/edge'
channel, enabling users to track nightly builds with:

    snap install yazi --classic --channel latest/edge

For draft releases, upload the built snaps to the 'latest/candidate'
channel.

And finally, when a release is published, promote the snaps that
are in the 'latest/candidate' channel to 'latest/stable'.

.github/workflows/draft.yml

@@ -187,6 +187,14 @@ jobs:
         with:
           merge-multiple: true
 
+      - name: Push snap to latest/candidate channel
+        env:
+          SNAPCRAFT_STORE_CREDENTIALS: ${{ secrets.SNAPCRAFT_TOKEN }}
+        run: |
+          for x in *.snap; do
+            snapcraft push -v --release latest/candidate $x
+          done
+
       - name: Draft
         uses: softprops/action-gh-release@v1
         with:
@@ -221,6 +229,14 @@ jobs:
           git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
           git tag --force nightly && git push --force origin tag nightly
 
+      - name: Push snap to latest/edge channel
+        env:
+          SNAPCRAFT_STORE_CREDENTIALS: ${{ secrets.SNAPCRAFT_TOKEN }}
+        run: |
+          for x in *.snap; do
+            snapcraft push -v --release latest/edge $x
+          done
+
       - name: Nightly
         uses: softprops/action-gh-release@v1
         with:

.github/workflows/publish.yml

@@ -18,3 +18,8 @@ jobs:
           identifier: sxyazi.yazi
           installers-regex: 'yazi-(x86_64|aarch64)-pc-windows-msvc\.zip$'
           token: ${{ secrets.WINGET_TOKEN }}
+
+      - name: Promote snap to latest/stable
+        env:
+          SNAPCRAFT_STORE_CREDENTIALS: ${{ secrets.SNAPCRAFT_TOKEN }}
+        run: snapcraft promote yazi --from-channel latest/candidate --to-channel latest/stable --yes