feat(echodata): add ECS calibration, local storage backend, and cal_params forwarding

- Add ecs.py: Echoview ECS file parsing via echopype's ECSParser with
  header normalization for Saildrone exports and dual-pulse support
- Refactor calibration.py: remove broken generic/ECS parsers, simplify
  apply_calibration to Saildrone-only, redirect .ecs to ecs.parse_ecs()
- Add local filesystem storage backend to storage.py: use_local_storage(),
  use_azure_storage(), is_local_storage() toggle, _LocalListFS for
  directory listing, local-mode paths in all save/open/upload functions
- Add cal_params parameter to compute_sv_from_echodata() for ECS-based
  calibration forwarding to echopype.calibrate.compute_Sv
- Guard _ensure_depth in nasc.py against depth already being a dimension
- Export new functions from echodata/__init__.py and calibrate/__init__.py

Author: beatfactor

oceanstream/echodata/__init__.py

@@ -415,6 +415,9 @@ def __getattr__(name: str):
         "open_sv_from_azure",
         "is_azure_configured",
         "list_campaign_data",
+        "use_local_storage",
+        "use_azure_storage",
+        "is_local_storage",
     ):
         from oceanstream.echodata.storage import (
             get_azure_zarr_store,
@@ -424,6 +427,9 @@ def __getattr__(name: str):
             open_sv_from_azure,
             is_azure_configured,
             list_campaign_data,
+            use_local_storage,
+            use_azure_storage,
+            is_local_storage,
         )
         return locals()[name]
 

oceanstream/echodata/calibrate/__init__.py

@@ -1,23 +1,36 @@
 """Calibration module for echosounder data.
 
-Provides functions for applying calibration values to EchoData objects,
-with support for Saildrone Excel calibration files.
+Two paths:
+
+* :func:`apply_calibration` (bake-time): mutates EchoData in place. Used by
+  the Saildrone Excel format.
+* :func:`build_cal_params_from_ecs` (Sv-time): returns echopype-compatible
+  ``env_params`` / ``cal_params`` dicts from one or two Echoview ECS files
+  (single- or dual-pulse).
 """
 
 from oceanstream.echodata.calibrate.calibration import (
     apply_calibration,
     load_calibration,
+    validate_calibration_params,
+)
+from oceanstream.echodata.calibrate.ecs import (
+    build_cal_params_from_ecs,
+    parse_ecs,
 )
 from oceanstream.echodata.calibrate.saildrone import (
     calibrate_saildrone,
-    load_saildrone_calibration,
     detect_pulse_mode,
+    load_saildrone_calibration,
 )
 
 __all__ = [
     "apply_calibration",
-    "load_calibration",
+    "build_cal_params_from_ecs",
     "calibrate_saildrone",
-    "load_saildrone_calibration",
     "detect_pulse_mode",
+    "load_calibration",
+    "load_saildrone_calibration",
+    "parse_ecs",
+    "validate_calibration_params",
 ]