fix: address all HIGH-severity code quality audit findings

- lsp/server.go: track request goroutines in inflight WaitGroup to
  prevent use-after-close writes on shutdown
- lsp/llm_client_registry.go: acquire write lock before calling build()
  to eliminate TOCTOU race on cache population
- lsp/handlers_codeaction.go: resolveSimplifyCodeAction now uses
  PromptCodeActionSimplify{System,User} (was wrongly using rewrite prompts)
- askcli/taskexport.go: remove exported MustParseTaskExport to prevent
  panic on malformed external input; move to unexported test helper
- cmd/ask/main.go: print error to stderr before os.Exit
- llm/{openai,ollama,openrouter}.go: add interface satisfaction assertions
- integrationtests/ask_test.go: replace type assertions with errors.As
  for robust exec.ExitError unwrapping

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/internal/lsp/handlers_codeaction.go b/internal/lsp/handlers_codeaction.go
index 1d8a36f..aba2113 100644
--- a/internal/lsp/handlers_codeaction.go
+++ b/internal/lsp/handlers_codeaction.go
@@ -266,10 +266,10 @@ func resolveGoTestCodeAction(s *Server, action CodeAction, payload codeActionPay
 
 func resolveSimplifyCodeAction(s *Server, action CodeAction, payload codeActionPayload) (CodeAction, bool) {
 	cfg := s.currentConfig()
-	sys := cfg.PromptCodeActionRewriteSystem
-	user := renderTemplate(cfg.PromptCodeActionRewriteUser, map[string]string{
-		"instruction": "Simplify and improve the code while preserving behavior. Return only the improved code.",
-		"selection":   payload.Selection,
+	// Use the simplify-specific prompts, not the rewrite prompts.
+	sys := cfg.PromptCodeActionSimplifySystem
+	user := renderTemplate(cfg.PromptCodeActionSimplifyUser, map[string]string{
+		"selection": payload.Selection,
 	})
 	return s.completeCodeAction(action, payload.URI, payload.Range, sys, user, 20*time.Second)
 }