refactor(prax): simplify logging from hierarchical to two-tier

Remove get_hierarchical_logs_dir() and all nested log placement logic.
Local logs now route to branch-root logs/ only, matching system_logs/
at repo root for a clean two-tier model.

Co-Authored-By: @prax <prax@aipass>

src/aipass/prax/apps/handlers/config/load.py

@@ -73,8 +73,7 @@ def get_module_logs_dir(module_name: str) -> Path:
     """Get the branch-root logs directory for a module.
 
     Returns ECOSYSTEM_ROOT / module_name / "logs", creating it if needed.
-    For hierarchical placement (logs at the caller's level), use
-    get_hierarchical_logs_dir() instead.
+    All branch-local logs are placed here (two-tier: system_logs/ + branch logs/).
 
     Args:
         module_name: Module name (e.g., "flow", "prax", "trigger")
@@ -86,43 +85,6 @@ def get_module_logs_dir(module_name: str) -> Path:
     logs_dir.mkdir(parents=True, exist_ok=True)
     return logs_dir
 
-
-def get_hierarchical_logs_dir(caller_path: str) -> Path:
-    """Get the logs directory at the caller's level in the code hierarchy.
-
-    Resolves a logs/ directory as a sibling of the caller's parent directory.
-    Logs live where the code lives:
-        handlers/dispatch/wake.py  → handlers/dispatch/logs/
-        modules/email.py           → modules/logs/
-        apps/branch.py             → apps/logs/
-
-    Falls back to branch-root logs/ if the caller is outside the
-    ecosystem or path resolution fails.
-
-    Args:
-        caller_path: Absolute path to the calling Python file
-
-    Returns:
-        Path to the logs directory (created if it doesn't exist)
-    """
-    try:
-        caller = Path(caller_path).resolve()
-        caller_dir = caller.parent
-
-        # Verify caller is inside the ecosystem
-        try:
-            caller.relative_to(ECOSYSTEM_ROOT)
-        except ValueError:
-            # Outside ecosystem — fall back to branch root
-            return get_module_logs_dir("prax")
-
-        logs_dir = caller_dir / "logs"
-        logs_dir.mkdir(parents=True, exist_ok=True)
-        return logs_dir
-
-    except Exception:
-        return get_module_logs_dir("prax")
-
 # Config file
 PRAX_LOGGER_CONFIG_FILE = PRAX_JSON_DIR / "prax_logger_config.json"
 

src/aipass/prax/apps/handlers/logging/setup.py

@@ -22,7 +22,6 @@ from logging.handlers import RotatingFileHandler
 from aipass.prax.apps.handlers.config.load import (
     get_system_logs_dir,
     get_module_logs_dir,
-    get_hierarchical_logs_dir,
     DEFAULT_LOG_LEVEL,
     load_log_config,
     lines_to_bytes
@@ -118,24 +117,9 @@ def setup_individual_logger(module_name: str) -> logging.Logger:
     system_handler.setFormatter(formatter)
     logger.addHandler(system_handler)
 
-    # HANDLER 2: Hierarchical local log (logs live where the code lives)
-    if module_path:
-        hierarchical_logs_dir = get_hierarchical_logs_dir(module_path)
-        # Detect fallback: caller was in ecosystem but resolution fell back
-        expected_logs = Path(module_path).resolve().parent / "logs"
-        if hierarchical_logs_dir.resolve() != expected_logs.resolve() and _system_logger:
-            _system_logger.warning(
-                f"Log placement fallback for {module_name}: "
-                f"caller outside ecosystem, logs redirected to {hierarchical_logs_dir}"
-            )
-    else:
-        hierarchical_logs_dir = get_module_logs_dir(branch_name)
-        if _system_logger:
-            _system_logger.warning(
-                f"Log placement fallback for {module_name}: "
-                f"stack introspection failed, using branch root {hierarchical_logs_dir}"
-            )
-    module_log_file = hierarchical_logs_dir / f"{module_name}.log"
+    # HANDLER 2: Branch-root local log (two-tier: system_logs/ + branch logs/)
+    local_logs_dir = get_module_logs_dir(branch_name)
+    module_log_file = local_logs_dir / f"{module_name}.log"
     local_limits = log_config['local_logs']
     local_max_bytes = lines_to_bytes(local_limits['max_lines'])
     local_handler = _safe_rotating_handler(module_log_file, local_max_bytes, local_limits['backup_count'])