feat: add Settings and Suite pages with comprehensive settings management and question suite builder

- Implemented SettingsPage for configuring default provider, temperature, and model paths.
- Added SuitePage for managing a suite of questions with features to add, edit, duplicate, and delete questions.
- Introduced TypeScript configuration files for app and node environments.
- Set up Vite configuration for development server with API proxying to backend.

server/suite.py

@@ -0,0 +1,73 @@
+"""Reading and writing the prompt suite in ``tests/``.
+
+The engine treats every ``tests/*.txt`` file as one prompt and derives its title
+from the first non-empty line, ordering files by a natural sort of their names.
+To keep the web editor and the ``auto-test.py`` CLI in perfect agreement, saving
+rewrites the directory as ``test1.txt`` … ``testN.txt`` in the order shown in
+the builder. That makes add / remove / reorder unambiguous for both entrypoints.
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+from typing import Dict, List
+
+from .core_bridge import TESTS_DIR, load_test_prompts
+
+
+class SuiteError(Exception):
+    """Raised when the suite on disk cannot be read or written."""
+
+
+def derive_title(prompt: str, fallback: str) -> str:
+    for line in prompt.splitlines():
+        stripped = line.strip()
+        if stripped:
+            return stripped
+    return fallback
+
+
+def list_tests() -> List[Dict[str, str]]:
+    """Return the suite exactly as the engine sees it."""
+    TESTS_DIR.mkdir(parents=True, exist_ok=True)
+    return load_test_prompts()
+
+
+def find_tests(filenames: List[str]) -> List[Dict[str, str]]:
+    """Return the prompts matching ``filenames``, preserving suite order."""
+    wanted = set(filenames)
+    selected = [prompt for prompt in list_tests() if prompt["filename"] in wanted]
+    missing = wanted - {prompt["filename"] for prompt in selected}
+    if missing:
+        raise SuiteError(f"Unknown test file(s): {', '.join(sorted(missing))}")
+    return selected
+
+
+def save_suite(prompts: List[str]) -> List[Dict[str, str]]:
+    """Replace the suite with ``prompts`` and return the resulting tests."""
+    cleaned = [text.strip() for text in prompts]
+    for position, text in enumerate(cleaned, start=1):
+        if not text:
+            raise SuiteError(f"Question {position} is empty. Remove it or add a prompt.")
+
+    TESTS_DIR.mkdir(parents=True, exist_ok=True)
+
+    target_names = {f"test{index}.txt" for index in range(1, len(cleaned) + 1)}
+    written: List[Path] = []
+
+    for index, text in enumerate(cleaned, start=1):
+        path = TESTS_DIR / f"test{index}.txt"
+        try:
+            path.write_text(text + "\n", encoding="utf-8")
+        except OSError as exc:
+            raise SuiteError(f"Could not write {path.name}: {exc}") from exc
+        written.append(path)
+
+    for stale in TESTS_DIR.glob("*.txt"):
+        if stale.name not in target_names:
+            try:
+                stale.unlink()
+            except OSError:
+                continue
+
+    return list_tests()