refactor(api): remove the natural-language elaborate REST endpoint (Phase 3)

Chatbots now elaborate tasks in-conversation and submit them via the chatbot
MCP server, so the POST /api/tasks/elaborate shell-out path is no longer needed.
Removes the route, handleElaborateTask, and the task-elaborate-only helpers
(buildElaboratePrompt, sanitizeElaboratedTask, readProjectContext,
appendRawNarrative, elaborateWith{Claude,Local,Gemini}, and the elaboratedTask/
elaboratedAgent types) plus their dedicated tests.

Shared helpers (extractJSON, claude/geminiBinaryPath, claude/geminiJSONResult,
elaborateTimeout, the per-IP limiter) are retained — the story-elaborate
endpoint and task-validate endpoint still use them. Stories themselves are
untouched here; their removal stays in the Phase 8 cleanup pass.

https://claude.ai/code/session_01SESwn7kQ7oP62trWw6pc39

1 files changed, 21 insertions, 0 deletions

diff --git a/internal/api/validate_test.go b/internal/api/validate_test.go
index c3d7b1f..60fec14 100644
--- a/internal/api/validate_test.go
+++ b/internal/api/validate_test.go
@@ -3,11 +3,32 @@ package api
 import (
 	"bytes"
 	"encoding/json"
+	"fmt"
 	"net/http"
 	"net/http/httptest"
+	"os"
+	"path/filepath"
 	"testing"
 )
 
+// createFakeClaude writes a stub `claude` script that prints the given output
+// and exits with the given code, returning its path for use as a binary
+// override in tests.
+func createFakeClaude(t *testing.T, output string, exitCode int) string {
+	t.Helper()
+	dir := t.TempDir()
+	outputFile := filepath.Join(dir, "output.json")
+	if err := os.WriteFile(outputFile, []byte(output), 0600); err != nil {
+		t.Fatal(err)
+	}
+	script := filepath.Join(dir, "claude")
+	content := fmt.Sprintf("#!/bin/sh\ncat %q\nexit %d\n", outputFile, exitCode)
+	if err := os.WriteFile(script, []byte(content), 0755); err != nil {
+		t.Fatal(err)
+	}
+	return script
+}
+
 func TestValidateTask_Success(t *testing.T) {
 	srv, _ := testServer(t)