feat(agent): implement recreate for devcontainers (#17308)

This change implements an interface for running `@devcontainers/cli up`
and an API endpoint on the agent for triggering recreate for a running
devcontainer.

A couple of limitations:

1. Synchronous HTTP request, meaning the browser might choose to time it
out before it's done => no result/error (and devcontainer cli command
probably gets killed via ctx cancel).
2. Logs are only written to agent logs via slog, not as a "script" in
the UI.

Both 1 and 2 will be improved in future refactors.

Fixes coder/internal#481
Fixes coder/internal#482

agent/agentcontainers/devcontainer.go

@@ -12,6 +12,15 @@ import (
 	"github.com/coder/coder/v2/codersdk"
 )
 
+const (
+	// DevcontainerLocalFolderLabel is the label that contains the path to
+	// the local workspace folder for a devcontainer.
+	DevcontainerLocalFolderLabel = "devcontainer.local_folder"
+	// DevcontainerConfigFileLabel is the label that contains the path to
+	// the devcontainer.json configuration file.
+	DevcontainerConfigFileLabel = "devcontainer.config_file"
+)
+
 const devcontainerUpScriptTemplate = `
 if ! which devcontainer > /dev/null 2>&1; then
   echo "ERROR: Unable to start devcontainer, @devcontainers/cli is not installed."
@@ -52,8 +61,10 @@ ScriptLoop:
 }
 
 func devcontainerStartupScript(dc codersdk.WorkspaceAgentDevcontainer, script codersdk.WorkspaceAgentScript) codersdk.WorkspaceAgentScript {
-	var args []string
-	args = append(args, fmt.Sprintf("--workspace-folder %q", dc.WorkspaceFolder))
+	args := []string{
+		"--log-format json",
+		fmt.Sprintf("--workspace-folder %q", dc.WorkspaceFolder),
+	}
 	if dc.ConfigPath != "" {
 		args = append(args, fmt.Sprintf("--config %q", dc.ConfigPath))
 	}