diff --git a/VERSION b/VERSION
index 33ac520..d15dfad 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.6.21
+0.6.22
diff --git a/actions/release-prepare/action.yml b/actions/release-prepare/action.yml
index 7e1b335..c805516 100644
--- a/actions/release-prepare/action.yml
+++ b/actions/release-prepare/action.yml
@@ -39,8 +39,13 @@ inputs:
     description: Read-only caller token used for planning and permission lookup.
     required: true
   app-id:
-    description: GitHub App id used for the short-lived mutation token.
-    required: true
+    description: Legacy GitHub App id retained for consumer compatibility.
+    required: false
+    default: ''
+  app-slug:
+    description: Public GitHub App slug used to resolve its client id.
+    required: false
+    default: librecode-workflow-automation
   app-private-key:
     description: GitHub App private key used for the short-lived mutation token.
     required: true
@@ -68,17 +73,13 @@ runs:
     - name: Validate GitHub App credentials
       shell: bash
       env:
-        RELEASE_APP_ID: ${{ inputs.app-id }}
+        RELEASE_APP_SLUG: ${{ inputs.app-slug }}
         RELEASE_APP_PRIVATE_KEY: ${{ inputs.app-private-key }}
       run: |
         set -euo pipefail
 
-        if [[ -z "${RELEASE_APP_ID}" ]]; then
-          echo "::error::GitHub App id is empty. Configure LIBRECODE_WORKFLOW_APP_ID as an Actions variable in the consumer repository or organization."
-          exit 1
-        fi
-        if [[ ! "${RELEASE_APP_ID}" =~ ^[0-9]+$ ]]; then
-          echo "::error::GitHub App id must be numeric."
+        if [[ -z "${RELEASE_APP_SLUG}" ]]; then
+          echo "::error::GitHub App slug is empty."
           exit 1
         fi
         if [[ -z "${RELEASE_APP_PRIVATE_KEY}" ]]; then
@@ -130,11 +131,29 @@ runs:
         echo "owner=${RELEASE_REPOSITORY%%/*}" >> "${GITHUB_OUTPUT}"
         echo "name=${RELEASE_REPOSITORY#*/}" >> "${GITHUB_OUTPUT}"
 
+    - id: app-identity
+      name: Resolve GitHub App client id
+      shell: bash
+      env:
+        RELEASE_APP_SLUG: ${{ inputs.app-slug }}
+        RELEASE_GITHUB_TOKEN: ${{ inputs.github-token }}
+        RELEASE_GITHUB_API_URL: ${{ github.api_url }}
+      run: |
+        set -euo pipefail
+
+        app_json="$(curl --fail --silent --show-error --location           -H "Accept: application/vnd.github+json"           -H "Authorization: Bearer ${RELEASE_GITHUB_TOKEN}"           -H "X-GitHub-Api-Version: 2022-11-28"           "${RELEASE_GITHUB_API_URL}/apps/${RELEASE_APP_SLUG}")"
+        client_id="$(php -r '$d=json_decode(stream_get_contents(STDIN),true,512,JSON_THROW_ON_ERROR); echo $d["client_id"] ?? "";' <<< "${app_json}")"
+        if [[ -z "${client_id}" ]]; then
+          echo "::error::GitHub App metadata did not contain a client_id for ${RELEASE_APP_SLUG}."
+          exit 1
+        fi
+        echo "client-id=${client_id}" >> "${GITHUB_OUTPUT}"
+
     - id: app-token
       name: Create scoped GitHub App token
       uses: actions/create-github-app-token@bcd2ba49218906704ab6c1aa796996da409d3eb1 # v3.2.0
       with:
-        app-id: ${{ inputs.app-id }}
+        client-id: ${{ steps.app-identity.outputs.client-id }}
         private-key: ${{ inputs.app-private-key }}
         owner: ${{ steps.repository.outputs.owner }}
         repositories: ${{ steps.repository.outputs.name }}
@@ -182,6 +201,25 @@ runs:
           printf -- '- State artifact: `%s`\n' "${artifact_name}"
         } >> "${GITHUB_STEP_SUMMARY}"
 
+    - name: Apply release pull request metadata
+      shell: bash
+      env:
+        GH_TOKEN: ${{ steps.app-token.outputs.token }}
+        RELEASE_REPOSITORY: ${{ github.repository }}
+        RELEASE_ACTOR: ${{ inputs.actor }}
+        RELEASE_PLAN_PATH: ${{ steps.plan.outputs.plan-path }}
+        RELEASE_PR_NUMBER: ${{ steps.prepare.outputs.pull-request-number }}
+      run: |
+        set -euo pipefail
+
+        milestone_number="$(php -r '$p=json_decode(file_get_contents($argv[1]),true,512,JSON_THROW_ON_ERROR); echo $p["milestone"]["number"] ?? "";' "${RELEASE_PLAN_PATH}")"
+        if [[ -z "${milestone_number}" ]]; then
+          echo "::error::ReleasePlan does not contain a milestone number."
+          exit 1
+        fi
+        payload="$(php -r 'echo json_encode(["assignees"=>[$argv[1]],"milestone"=>(int)$argv[2]],JSON_THROW_ON_ERROR);' "${RELEASE_ACTOR}" "${milestone_number}")"
+        printf '%s' "${payload}" | gh api           --method PATCH           "repos/${RELEASE_REPOSITORY}/issues/${RELEASE_PR_NUMBER}"           --input -           >/dev/null
+
     - name: Persist release preparation contracts
       uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
       with:
diff --git a/tests/test_release_prepare_action.py b/tests/test_release_prepare_action.py
index b297180..2bcb8ed 100644
--- a/tests/test_release_prepare_action.py
+++ b/tests/test_release_prepare_action.py
@@ -26,16 +26,22 @@ def test_prepare_composes_policy_contracts_and_scoped_mutation(self) -> None:
         self.assertIn("permission-contents: write", content)
         self.assertIn("permission-pull-requests: write", content)
         self.assertNotIn("permission-workflows: write", content)
+        self.assertIn("client-id: ${{ steps.app-identity.outputs.client-id }}", content)
+        self.assertNotIn("app-id: ${{ inputs.app-id }}", content)
         self.assertIn("release:prepare", content)
+        self.assertIn("Apply release pull request metadata", content)
+        self.assertIn('"assignees"=>[$argv[1]]', content)
+        self.assertIn('"milestone"=>(int)$argv[2]', content)
 
     def test_prepare_validates_mutation_credentials_before_planning(self) -> None:
         content = ACTION.read_text(encoding="utf-8")
         validate = content.index("Validate GitHub App credentials")
         plan = content.index("Build release plan")
         self.assertLess(validate, plan)
-        self.assertIn("LIBRECODE_WORKFLOW_APP_ID", content)
         self.assertIn("LIBRECODE_WORKFLOW_APP_PRIVATE_KEY", content)
-        self.assertIn('[[ ! "${RELEASE_APP_ID}" =~ ^[0-9]+$ ]]', content)
+        self.assertIn("librecode-workflow-automation", content)
+        self.assertIn("/apps/${RELEASE_APP_SLUG}", content)
+        self.assertIn('"client_id"', content)
 
     def test_prepare_persists_plan_and_preparation_by_pr_number(self) -> None:
         content = ACTION.read_text(encoding="utf-8")