fix: permission-prompt-tool response format and scaffold .claude/settings.json

- Return { behavior: "allow", updatedInput: <input> } from prompt_permission
  to match the Claude Code SDK expected format (was returning just
  { behavior: "allow" } which failed validation)
- Scaffold .claude/settings.json with sensible permission defaults (Edit,
  Write, common Bash commands, mcp__story-kit__*) so fresh projects don't
  trigger constant permission prompts

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

server/src/http/mcp.rs

@@ -1816,7 +1816,7 @@ async fn tool_prompt_permission(args: &Value, ctx: &AppContext) -> Result<String
         .send(crate::http::context::PermissionForward {
             request_id: request_id.clone(),
             tool_name: tool_name.clone(),
-            tool_input,
+            tool_input: tool_input.clone(),
             response_tx,
         })
         .map_err(|_| "No active WebSocket session to receive permission request".to_string())?;
@@ -1834,11 +1834,10 @@ async fn tool_prompt_permission(args: &Value, ctx: &AppContext) -> Result<String
     .map_err(|_| "Permission response channel closed unexpectedly".to_string())?;
 
     if approved {
-        // Claude Code SDK validates the response as a union:
+        // Claude Code SDK expects:
-        //   { behavior: "allow" } | { behavior: "deny", message: string }
+        //   Allow:  { behavior: "allow", updatedInput: <record> }
-        // Previously we returned {"updatedInput": ...} which didn't match
+        //   Deny:   { behavior: "deny", message: string }
-        // either variant, causing intermittent `invalid_union` errors.
+        Ok(json!({"behavior": "allow", "updatedInput": tool_input}).to_string())
-        Ok(json!({"behavior": "allow"}).to_string())
     } else {
         slog_warn!("[permission] User denied permission for '{tool_name}'");
         Ok(json!({
@@ -3374,7 +3373,7 @@ stage = "coder"
     }
 
     #[tokio::test]
-    async fn tool_prompt_permission_approved_returns_allow_behavior() {
+    async fn tool_prompt_permission_approved_returns_updated_input() {
         let tmp = tempfile::tempdir().unwrap();
         let ctx = test_ctx(tmp.path());
 
@@ -3397,7 +3396,11 @@ stage = "coder"
         let parsed: Value = serde_json::from_str(&result).expect("result should be valid JSON");
         assert_eq!(
             parsed["behavior"], "allow",
-            "approved must return behavior:allow for Claude Code SDK compatibility"
+            "approved must return behavior:allow"
+        );
+        assert_eq!(
+            parsed["updatedInput"]["command"], "echo hello",
+            "approved must return updatedInput with original tool input for Claude Code SDK compatibility"
         );
     }
 

server/src/io/fs.rs

@@ -60,6 +60,46 @@ parallel calls work fine.\n\
 \n\
 Read .story_kit/README.md to see our dev process.\n";
 
+const STORY_KIT_CLAUDE_SETTINGS: &str = r#"{
+  "permissions": {
+    "allow": [
+      "Bash(cargo build:*)",
+      "Bash(cargo check:*)",
+      "Bash(cargo clippy:*)",
+      "Bash(cargo test:*)",
+      "Bash(cargo run:*)",
+      "Bash(cargo nextest run:*)",
+      "Bash(git *)",
+      "Bash(ls *)",
+      "Bash(mkdir *)",
+      "Bash(mv *)",
+      "Bash(rm *)",
+      "Bash(touch *)",
+      "Bash(echo:*)",
+      "Bash(pwd *)",
+      "Bash(pnpm install:*)",
+      "Bash(pnpm run build:*)",
+      "Bash(pnpm run test:*)",
+      "Bash(pnpm test:*)",
+      "Bash(pnpm build:*)",
+      "Bash(npm run build:*)",
+      "Bash(npx tsc:*)",
+      "Bash(npx vitest:*)",
+      "Bash(npx @biomejs/biome check:*)",
+      "Bash(npx playwright test:*)",
+      "Bash(script/test:*)",
+      "Bash(./script/test:*)",
+      "Edit",
+      "Write",
+      "mcp__story-kit__*"
+    ]
+  },
+  "enabledMcpjsonServers": [
+    "story-kit"
+  ]
+}
+"#;
+
 const DEFAULT_PROJECT_TOML: &str = r#"[[agent]]
 name = "coder-1"
 stage = "coder"
@@ -263,6 +303,14 @@ fn scaffold_story_kit(root: &Path) -> Result<(), String> {
     write_script_if_missing(&script_root.join("test"), STORY_KIT_SCRIPT_TEST)?;
     write_file_if_missing(&root.join("CLAUDE.md"), STORY_KIT_CLAUDE_MD)?;
 
+    // Create .claude/settings.json with sensible permission defaults so that
+    // Claude Code (both agents and web UI chat) can operate without constant
+    // permission prompts.
+    let claude_dir = root.join(".claude");
+    fs::create_dir_all(&claude_dir)
+        .map_err(|e| format!("Failed to create .claude/ directory: {}", e))?;
+    write_file_if_missing(&claude_dir.join("settings.json"), STORY_KIT_CLAUDE_SETTINGS)?;
+
     append_gitignore_entries(root)?;
 
     // Run `git init` if the directory is not already a git repo, then make an initial commit
@@ -277,7 +325,7 @@ fn scaffold_story_kit(root: &Path) -> Result<(), String> {
         }
 
         let add_output = std::process::Command::new("git")
-            .args(["add", ".story_kit", "script", ".gitignore", "CLAUDE.md"])
+            .args(["add", ".story_kit", "script", ".gitignore", "CLAUDE.md", ".claude"])
             .current_dir(root)
             .output()
             .map_err(|e| format!("Failed to run git add: {}", e))?;