docs: add security reporting policy (#2561)

* docs(security): add private reporting policy

Document supported versions and route vulnerability reports through GitHub's private advisory workflow.

Add English and Chinese responsible-use notices to the READMEs.

Closes #2544

* ci: skip unrelated pull request builds

Use pull-request-aware path filtering for required Core, GUI, Mobile, and Test workflows so they still publish required check contexts without launching expensive jobs for documentation changes.

Limit the optional OHOS pull request workflow to relevant paths.

.github/workflows/test.yml

@@ -22,19 +22,40 @@ defaults:
 
 jobs:
   pre_job:
-    # continue-on-error: true # Uncomment once integration is finished
     runs-on: ubuntu-latest
-    # Map a step output to a job output
+    env:
+      RELEVANT_PATHS: >-
+        ["Cargo.toml", "Cargo.lock", "rust-toolchain.toml", ".cargo/**",
+        "pnpm-lock.yaml", "pnpm-workspace.yaml", "package.json", "easytier/**",
+        "easytier-core/**", "easytier-proto/**", "easytier-rpc-build/**",
+        "easytier-web/**", "easytier-gui/src-tauri/**",
+        "tauri-plugin-vpnservice/**", "easytier-contrib/**",
+        ".github/workflows/test.yml", ".github/actions/**"]
     outputs:
-      should_skip: ${{ steps.skip_check.outputs.should_skip }}
+      should_skip: >-
+        ${{
+          steps.skip_check.outputs.should_skip == 'true' ||
+          (
+            github.event_name == 'pull_request' &&
+            steps.path_filter.outputs.relevant != 'true'
+          )
+        }}
     steps:
       - id: skip_check
         uses: fkirc/skip-duplicate-actions@v5
         with:
-          # All of these options are optional, so you can remove them if you are happy with the defaults
           concurrent_skipping: 'never'
           skip_after_successful_duplicate: 'true'
-          paths: '["Cargo.toml", "Cargo.lock", "easytier/**", "easytier-core/**", "easytier-proto/**", "easytier-web/**", "easytier-gui/src-tauri/**", "easytier-contrib/**", ".github/workflows/test.yml", ".github/actions/**"]'
+          paths: ${{ env.RELEVANT_PATHS }}
+
+      - id: path_filter
+        if: >-
+          github.event_name == 'pull_request' &&
+          steps.skip_check.outputs.should_skip != 'true'
+        uses: dorny/paths-filter@v4
+        with:
+          filters: |
+            relevant: ${{ env.RELEVANT_PATHS }}
 
   check:
     name: Run linters & check