Keep resumed /status JSON aligned with live status output

The resumed slash-command path built a reduced status JSON payload by hand, so it drifted from the fresh status schema and dropped metadata like model, permission mode, workspace counters, and sandbox details. Reuse a shared status JSON builder for both code paths and tighten the resume regression tests to lock parity in place.

Constraint: Resume mode does not carry an active runtime model, so restored sessions continue to report the existing restored-session sentinel value
Rejected: Copy the fresh status JSON shape into the resume path again | would recreate the same schema drift risk
Confidence: high
Scope-risk: narrow
Directive: Keep resumed and fresh /status JSON on the same helper so future schema changes stay in parity
Tested: Reproduced failure in temporary HEAD worktree with strengthened resumed_status_command_emits_structured_json_when_requested
Tested: cargo test -p rusty-claude-cli resumed_status_command_emits_structured_json_when_requested --test resume_slash_commands -- --exact --nocapture
Tested: cargo test -p rusty-claude-cli doctor_and_resume_status_emit_json_when_requested --test output_format_contract -- --exact --nocapture
Tested: cargo test --workspace
Tested: cargo fmt --check
Tested: cargo clippy --workspace --all-targets -- -D warnings

rust/crates/rusty-claude-cli/tests/output_format_contract.rs

@@ -130,7 +130,10 @@ fn doctor_and_resume_status_emit_json_when_requested() {
         ],
     );
     assert_eq!(resumed["kind"], "status");
-    assert_eq!(resumed["messages"], 1);
+    assert_eq!(resumed["model"], "restored-session");
+    assert_eq!(resumed["usage"]["messages"], 1);
+    assert!(resumed["workspace"]["cwd"].as_str().is_some());
+    assert!(resumed["sandbox"]["filesystem_mode"].as_str().is_some());
 }
 
 fn assert_json_command(current_dir: &Path, args: &[&str]) -> Value {

rust/crates/rusty-claude-cli/tests/resume_slash_commands.rs

@@ -261,11 +261,18 @@ fn resumed_status_command_emits_structured_json_when_requested() {
     let parsed: Value =
         serde_json::from_str(stdout.trim()).expect("resume status output should be json");
     assert_eq!(parsed["kind"], "status");
-    assert_eq!(parsed["messages"], 1);
+    assert_eq!(parsed["model"], "restored-session");
+    assert_eq!(parsed["permission_mode"], "danger-full-access");
+    assert_eq!(parsed["usage"]["messages"], 1);
+    assert!(parsed["usage"]["turns"].is_number());
+    assert!(parsed["workspace"]["cwd"].as_str().is_some());
     assert_eq!(
         parsed["workspace"]["session"],
         session_path.to_str().expect("utf8 path")
     );
+    assert!(parsed["workspace"]["changed_files"].is_number());
+    assert_eq!(parsed["workspace"]["loaded_config_files"].as_u64(), Some(0));
+    assert!(parsed["sandbox"]["filesystem_mode"].as_str().is_some());
 }
 
 fn run_claw(current_dir: &Path, args: &[&str]) -> Output {