feat: add path helper functions to file_service

- get_app_dir(): project root in dev, exe dir in PyInstaller bundle
- get_resource_path/get_config_path: paths under app dir
- get_log_dir/get_output_dir: auto-create and return logs/ and output/
- Refactor log_service to use get_log_dir() instead of own __file__ calc

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

src/services/log_service.py

@@ -6,28 +6,32 @@ from datetime import datetime
 def setup_logging(log_dir=None):
     """Initialize file + console logging. Call once at application startup.
 
-    log_dir: absolute path to log directory. Defaults to <project_root>/logs/.
-    If the directory cannot be created, falls back to console-only logging.
+    log_dir: str or Path to log directory. Defaults to <app_dir>/logs/ via
+             file_service.get_log_dir(). Falls back to console-only if the
+             directory cannot be created.
     """
     if log_dir is None:
-        # src/services/log_service.py -> src/services -> src -> project root
-        _here = os.path.dirname(os.path.abspath(__file__))
-        log_dir = os.path.join(os.path.dirname(os.path.dirname(_here)), "logs")
-
-    try:
-        os.makedirs(log_dir, exist_ok=True)
-    except OSError as exc:
-        logging.basicConfig(
-            level=logging.INFO,
-            format="%(asctime)s %(name)s %(levelname)s %(message)s",
-        )
-        logging.getLogger(__name__).warning(
-            "Cannot create log directory %s: %s. Falling back to console only.", log_dir, exc
-        )
-        return
+        try:
+            from services.file_service import get_log_dir
+            log_dir = get_log_dir()
+        except OSError as exc:
+            _setup_console_only()
+            logging.getLogger(__name__).warning(
+                "Cannot create log directory: %s. Falling back to console only.", exc
+            )
+            return
+    else:
+        try:
+            os.makedirs(str(log_dir), exist_ok=True)
+        except OSError as exc:
+            _setup_console_only()
+            logging.getLogger(__name__).warning(
+                "Cannot create log directory %s: %s. Falling back to console only.", log_dir, exc
+            )
+            return
 
     timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
-    log_file = os.path.join(log_dir, "app_{}.log".format(timestamp))
+    log_file = os.path.join(str(log_dir), "app_{}.log".format(timestamp))
 
     formatter = logging.Formatter("%(asctime)s %(name)s %(levelname)s %(message)s")
 
@@ -43,3 +47,10 @@ def setup_logging(log_dir=None):
     root.addHandler(sh)
 
     logging.getLogger(__name__).info("Logging initialized. Log file: %s", log_file)
+
+
+def _setup_console_only():
+    logging.basicConfig(
+        level=logging.INFO,
+        format="%(asctime)s %(name)s %(levelname)s %(message)s",
+    )