Show logs when a build fails before the "build" phase starts

[ipmb]

We only stream build and test (aka postbuild) logs in the client, but there are scenarios where a build could fail in other phases. Prebuild is a common one when app.json or apppack.toml are not properly formatted. In those scenarios, we should output the relevant logs so users can see what happened.

example prebuild failure raw logs

[Container] 2025/07/17 20:53:39.016370 Running on CodeBuild On-demand
[Container] 2025/07/17 20:53:39.016385 Waiting for agent ping
[Container] 2025/07/17 20:53:40.221146 Waiting for DOWNLOAD_SOURCE
[Container] 2025/07/17 20:53:41.794309 Phase is DOWNLOAD_SOURCE
[Container] 2025/07/17 20:53:41.796088 CODEBUILD_SRC_DIR=/codebuild/output/src251170741/src/github.com/org/repo
[Container] 2025/07/17 20:53:41.796655 YAML location is /codebuild/readonly/buildspec.yml
[Container] 2025/07/17 20:53:41.801226 Setting HTTP client timeout to higher timeout for Github and GitHub Enterprise sources
[Container] 2025/07/17 20:53:41.801397 Processing environment variables
[Container] 2025/07/17 20:53:41.858424 Moving to directory /codebuild/output/src251170741/src/github.com/org/repo
[Container] 2025/07/17 20:53:41.858446 Cache is not defined in the buildspec
[Container] 2025/07/17 20:53:41.891646 Skip cache due to: no paths specified to be cached
[Container] 2025/07/17 20:53:41.891944 Registering with agent
[Container] 2025/07/17 20:53:41.921956 Phases found in YAML: 4
[Container] 2025/07/17 20:53:41.921971  BUILD: 1 commands
[Container] 2025/07/17 20:53:41.921976  INSTALL: 4 commands
[Container] 2025/07/17 20:53:41.921980  POST_BUILD: 1 commands
[Container] 2025/07/17 20:53:41.921983  PRE_BUILD: 1 commands
[Container] 2025/07/17 20:53:41.922418 Phase complete: DOWNLOAD_SOURCE State: SUCCEEDED
[Container] 2025/07/17 20:53:41.922430 Phase context status code:  Message: 
[Container] 2025/07/17 20:53:42.521431 Entering phase INSTALL
[Container] 2025/07/17 20:53:42.553646 Running command if [ -z "$CODEBUILD_START_TIME" ]; then exit 0; fi
[Container] 2025/07/17 20:53:42.560506 Running command echo "Starting Docker daemon..."
Starting Docker daemon...
[Container] 2025/07/17 20:53:42.568107 Running command nohup /usr/local/bin/dockerd --host=unix:///var/run/docker.sock --host=tcp://127.0.0.1:2375 --storage-driver=overlay2 --registry-mirror=https://registry.apppackcdn.net &> /var/lib/docker.log &
[Container] 2025/07/17 20:53:42.573477 Running command for i in $(seq 1 10); do docker info > /dev/null 2>&1 && break || sleep 0.5; done
[Container] 2025/07/17 20:53:46.329196 Phase complete: INSTALL State: SUCCEEDED
[Container] 2025/07/17 20:53:46.329218 Phase context status code:  Message: 
[Container] 2025/07/17 20:53:46.361218 Entering phase PRE_BUILD
[Container] 2025/07/17 20:53:46.362687 Running command apppack-builder prebuild
20:53:46 ERR failed to parse app.json error="invalid character '/' after object key:value pair"
20:53:46 FTL Error error="invalid character '/' after object key:value pair"
[Container] 2025/07/17 20:53:46.379706 Command did not exit successfully apppack-builder prebuild exit status 1
[Container] 2025/07/17 20:53:46.383610 Phase complete: PRE_BUILD State: FAILED
[Container] 2025/07/17 20:53:46.383628 Phase context status code: COMMAND_EXECUTION_ERROR Message: Error while executing command: apppack-builder prebuild. Reason: exit status 1