fix: critical parity bugs - enable tools, default permissions, tool input

Tighten prompt-mode parity for the Rust CLI by enabling native tools in one-shot runs, defaulting fresh sessions to danger-full-access, and documenting the remaining TS-vs-Rust gaps.

The JSON prompt path now runs through the full conversation loop so tool use and tool results are preserved without streaming terminal noise, while the tool-input accumulator keeps the streaming {} placeholder fix without corrupting legitimate non-stream empty objects.

Constraint: Original TypeScript source was treated as read-only for parity analysis
Constraint: No new dependencies; keep the fix localized to the Rust port
Rejected: Leave JSON prompt mode on a direct non-tool API path | preserved the one-shot parity bug
Rejected: Keep workspace-write as the default permission mode | contradicted requested parity target
Confidence: high
Scope-risk: moderate
Reversibility: clean
Directive: Keep prompt text and prompt JSON paths on the same tool-capable runtime semantics unless upstream behavior proves they must diverge
Tested: cargo build --release; cargo test
Not-tested: live remote prompt run against LayoffLabs endpoint in this session

rust/crates/rusty-claude-cli/src/app.rs

@@ -386,13 +386,13 @@ mod tests {
     fn session_state_tracks_config_values() {
         let config = SessionConfig {
             model: "claude".into(),
-            permission_mode: PermissionMode::WorkspaceWrite,
+            permission_mode: PermissionMode::DangerFullAccess,
             config: Some(PathBuf::from("settings.toml")),
             output_format: OutputFormat::Text,
         };
 
         assert_eq!(config.model, "claude");
-        assert_eq!(config.permission_mode, PermissionMode::WorkspaceWrite);
+        assert_eq!(config.permission_mode, PermissionMode::DangerFullAccess);
         assert_eq!(config.config, Some(PathBuf::from("settings.toml")));
     }
 }