Do not strip suffixes from suggested internal names

Suffixes like '_r0', '_t0' etc. represent transformation chains in NeXus,
not arbitrary naming conventions. These should be preserved in the suggested
internal names.

Changes:
- Remove regex-based suffix stripping from suggest_internal_name()
- Update docstring to remove misleading example about suffix removal
- Rename tests test_removes_r0_suffix → test_preserves_r0_suffix
- Rename tests test_removes_t0_suffix → test_preserves_t0_suffix
- Update test expectations to preserve suffixes

Note: The bifrost f144_log_streams configuration was generated with the old
code that stripped suffixes. However, examining the current stream names
(attenuator_1, temperature_0, etc.), none appear to match the pattern
'_[rt]\d+$' that was being stripped, so no regeneration is needed at this
time. If the original NeXus file contained streams with '_r0' or '_t0'
suffixes, they would need to be regenerated to ensure accuracy.

Original prompt: Please use a worktree and address the suffix-removal problem
discussed in #589 (do not strip _r0 and the like, since it refers to "rotation 0",
in fact do not strip any suffixes). Do we need to rerun the scripts that were used
to generate the dict of names for bifrost?

Author: SimonHeybrock

src/ess/livedata/nexus_helpers.py

@@ -125,18 +125,14 @@ def suggest_internal_name(info: StreamInfo) -> str:
     """Suggest an internal name based on the group path.
 
     Uses the parent group name (last path component before 'value', 'idle_flag', etc.)
-    as the basis for the internal name, converting to snake_case.
+    as the basis for the internal name.
     """
     parts = info.group_path.split('/')
     # For paths like '.../rotation_stage/value', use 'rotation_stage'
-    # For paths like '.../detector_tank_angle_r0/value', use 'detector_tank_angle'
     for i, part in enumerate(parts):
         if part in ('value', 'idle_flag', 'target_value'):
             if i > 0:
-                name = parts[i - 1]
-                # Remove common suffixes like '_r0', '_01' etc.
-                name = re.sub(r'_[rt]\d+$', '', name)
-                return name
+                return parts[i - 1]
     # Fallback: use last non-value component
     return parts[-2] if len(parts) >= 2 else parts[-1]
 

tests/nexus_helpers_test.py

@@ -424,7 +424,7 @@ def test_extracts_name_before_idle_flag(self) -> None:
         )
         assert suggest_internal_name(info) == 'rotation_stage'
 
-    def test_removes_r0_suffix(self) -> None:
+    def test_preserves_r0_suffix(self) -> None:
         info = StreamInfo(
             group_path='entry/instrument/detector_tank_angle_r0/value',
             topic='motion',
@@ -433,9 +433,9 @@ def test_removes_r0_suffix(self) -> None:
             parent_nx_class='NXpositioner',
             writer_module='f144',
         )
-        assert suggest_internal_name(info) == 'detector_tank_angle'
+        assert suggest_internal_name(info) == 'detector_tank_angle_r0'
 
-    def test_removes_t0_suffix(self) -> None:
+    def test_preserves_t0_suffix(self) -> None:
         info = StreamInfo(
             group_path='entry/instrument/sample_stage_t0/value',
             topic='motion',
@@ -444,7 +444,7 @@ def test_removes_t0_suffix(self) -> None:
             parent_nx_class='NXpositioner',
             writer_module='f144',
         )
-        assert suggest_internal_name(info) == 'sample_stage'
+        assert suggest_internal_name(info) == 'sample_stage_t0'
 
 
 class TestFilterF144Streams: