fix: smoke-test agent images after build, add start --no-cache

npm treats optionalDependencies failures as non-fatal, so a transient
network blip fetching claude-code's platform-native binary during
`npm install -g` left a stub CLI in an image that still "built"
successfully — then got baked into the Docker/Container layer cache
until forced to rebuild. Post-build smoke test (provider-declared
argv, run in a throwaway container of the freshly built image) fails
the launch loudly instead of shipping a broken image; --no-cache
gives an escape hatch to force a from-scratch rebuild.

Closes #353.

bot_bottle/contrib/claude/agent_provider.py

@@ -91,6 +91,7 @@ _RUNTIME = AgentProviderRuntime(
     prompt_mode="append_file",
     bypass_args=("--dangerously-skip-permissions",),
     resume_args=("--continue",),
+    smoke_test=("claude", "--version"),
 )