Add chunk plan cache configuration and storage

internal/core/config/config.go

@@ -38,11 +38,17 @@ type DiagnosticsConfig struct {
 
 type WorkspaceConfig struct {
 	Directory   string                     `json:"directory,omitempty"`
+	ChunkCache  WorkspaceChunkCacheConfig  `json:"chunk_cache"`
 	Diagnostics WorkspaceDiagnosticsConfig `json:"diagnostics"`
 	Resume      WorkspaceResumeConfig      `json:"resume"`
 	Debug       WorkspaceDebugConfig       `json:"debug"`
 }
 
+type WorkspaceChunkCacheConfig struct {
+	Mode      pipeline.ChunkCacheMode `json:"mode"`
+	Directory string                  `json:"directory,omitempty"`
+}
+
 type WorkspaceDiagnosticsConfig struct {
 	Enabled      bool                      `json:"enabled"`
 	Retention    diagnostics.RetentionMode `json:"retention,omitempty"`
@@ -71,6 +77,7 @@ func Default() Config {
 			Retention: diagnostics.RetentionAuto,
 		},
 		Workspace: WorkspaceConfig{
+			ChunkCache: WorkspaceChunkCacheConfig{Mode: pipeline.ChunkCacheAuto},
 			Diagnostics: WorkspaceDiagnosticsConfig{
 				Enabled: true,
 			},