ci: move packaging to main and remove repeated CLI suites

PR runners were rebuilding distribution artifacts and executing the entire CLI source suite on all three E2E shards. Keep packaging coverage after merge, let the local E2E runner own its dependency build, and execute source tests once in an existing required check. Root typecheck already validates plugin examples.

.github/workflows/docker.yml

@@ -1,27 +1,6 @@
 name: Docker
 
 on:
-  pull_request:
-    branches: [main]
-    paths:
-      - "docker/**"
-      - ".dockerignore"
-      - ".github/workflows/docker.yml"
-      - "package.json"
-      - "package-lock.json"
-      - "patches/**"
-      - "scripts/**"
-      - "tsconfig.json"
-      - "tsconfig.base.json"
-      - "packages/app/**"
-      - "packages/cli/**"
-      - "packages/client/**"
-      - "packages/expo-two-way-audio/**"
-      - "packages/highlight/**"
-      - "packages/plugin/**"
-      - "packages/protocol/**"
-      - "packages/relay/**"
-      - "packages/server/**"
   push:
     branches: [main]
     tags:
@@ -51,7 +30,7 @@ on:
 
 concurrency:
   group: docker-${{ github.workflow }}-${{ github.ref }}
-  cancel-in-progress: ${{ github.event_name == 'pull_request' }}
+  cancel-in-progress: false
 
 env:
   REGISTRY: ghcr.io