make no-cache the default and drop the workflow flag

Default 'agentex agents build' to --no-cache instead of forcing it in the
publish workflow. A bare 'agentex agents build' is now cache-free, so the
build-and-push workflow needs no change and the diff shrinks to the CLI.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: deepthi-rao-scale

.github/workflows/build-and-push-tutorial-agent.yml

@@ -196,10 +196,8 @@ jobs:
             echo "SKIP_VALIDATION=true" >> $GITHUB_ENV
           fi
 
-          # Always build without cache: a stale cached layer must never silently ship
-          # source that differs from the checkout (this is how a merged fix once failed
-          # to reach ':latest'). Correctness over a few minutes of build time.
-          BUILD_ARGS="--manifest ${{ matrix.agent_path }}/manifest.yaml --registry ${REGISTRY} --tag ${VERSION_TAG} --platforms linux/amd64,linux/arm64 --repository-name ${REPOSITORY_NAME} --no-cache"
+          # Always build locally first (without push)
+          BUILD_ARGS="--manifest ${{ matrix.agent_path }}/manifest.yaml --registry ${REGISTRY} --tag ${VERSION_TAG} --platforms linux/amd64,linux/arm64 --repository-name ${REPOSITORY_NAME}"
 
           agentex agents build $BUILD_ARGS
           echo "✅ Successfully built: ${REGISTRY}/${REPOSITORY_NAME}:${VERSION_TAG}"

src/agentex/lib/cli/commands/agents.py

@@ -128,10 +128,11 @@ def build(
         help="Docker build argument in the format 'KEY=VALUE' (can be used multiple times)",
     ),
     cache: bool = typer.Option(
-        True,
+        False,
         "--cache/--no-cache",
-        help="Use the build cache (default). Pass --no-cache when republishing a moving "
-        "tag like ':latest' so a stale cached layer can't ship outdated source.",
+        help="Whether to use the build cache. Defaults to off so a stale cached layer "
+        "can't silently ship source that no longer matches the checkout (notably when "
+        "republishing a moving tag like ':latest'). Pass --cache to opt back in.",
     ),
 ):
     """

src/agentex/lib/cli/handlers/agent_handlers.py

@@ -39,7 +39,7 @@ def build_agent(
     secret: str | None = None,
     tag: str | None = None,
     build_args: list[str] | None = None,
-    cache: bool = True,
+    cache: bool = False,
 ) -> str:
     """Build the agent locally and optionally push to registry
 
@@ -50,10 +50,10 @@ def build_agent(
         secret: Docker build secret in format 'id=secret-id,src=path-to-secret-file'
         tag: Image tag to use (defaults to 'latest')
         build_args: List of Docker build arguments in format 'KEY=VALUE'
-        cache: Whether to use the build cache. Defaults to True. Set to False (passes
-            --no-cache to buildx) when republishing a moving tag like ':latest' so a
-            stale cached layer can't silently ship source that no longer matches the
-            checkout.
+        cache: Whether to use the build cache. Defaults to False (passes --no-cache to
+            buildx) so a stale cached layer can't silently ship source that no longer
+            matches the checkout, notably when republishing a moving tag like ':latest'.
+            Pass True to opt back in for faster local rebuilds.
 
     Returns:
         The image URL