chore(go): audit providers kimi grok qwen letta

Move Kimi, Grok, and Qwen onto managed_runtime.go and shell_command.go;
share the encoded and shell command builders and the quoted Windows
legacy parser with Droid; split managed_changes.go; dedupe Letta's hook
entry filtering and stop swallowing settings read errors.

Claude-Session: https://claude.ai/code/session_01Agoc9bRVE9KL7mmWtey9Vq

cmd/elydora/plugins/qwen_recovery_test.go

@@ -244,7 +244,7 @@ func TestQwenTransactionRollsBackAllFilesAndCleansStaging(t *testing.T) {
 	original := readQwenTestFile(t, fixture.configPath)
 	failed := false
 	fixture.plugin.rename = func(source, destination string) error {
-		if !failed && sameQwenPath(destination, fixture.configPath) {
+		if !failed && sameManagedPath(destination, fixture.configPath) {
 			failed = true
 			return errors.New("simulated settings commit failure")
 		}