fix(tap-uk-ees): inject time_period from release slug when absent in CSV

Older census (and other) files don't include a time_period column.
Derive it from the release slug (e.g. '2022-23' → '202223') and inject
it into records so the required Singer schema field is always present.

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

pipeline/plugins/extractors/tap-uk-ees/tap_uk_ees/tap.py

@@ -31,15 +31,27 @@ def get_content_release_id(publication_slug: str) -> str:
     return resp.json()["id"]
 
 
-def get_all_release_ids(publication_slug: str) -> list[str]:
-    """Return all release IDs for a publication, newest first."""
+def _slug_to_time_period(slug: str) -> str | None:
+    """Convert a release slug like '2022-23' to a time_period like '202223'."""
+    parts = slug.split("-")
+    if len(parts) == 2 and len(parts[0]) == 4 and len(parts[1]) == 2:
+        return parts[0] + parts[1]
+    return None
+
+
+def get_all_releases(publication_slug: str) -> list[dict]:
+    """Return all releases for a publication as dicts with 'id' and 'time_period'."""
     url = f"{CONTENT_API_BASE}/publications/{publication_slug}/releases"
     resp = requests.get(url, timeout=TIMEOUT)
     resp.raise_for_status()
     data = resp.json()
     # API returns either a plain list or a paginated object with a "results" key
     releases = data if isinstance(data, list) else data.get("results", [])
-    return [r["id"] for r in releases]
+    result = []
+    for r in releases:
+        time_period = _slug_to_time_period(r.get("slug", ""))
+        result.append({"id": r["id"], "time_period": time_period})
+    return result
 
 
 def download_release_zip(release_id: str) -> zipfile.ZipFile:
@@ -71,15 +83,18 @@ class EESDatasetStream(Stream):
 
         latest_only = self.config.get("latest_only", False)
         if latest_only:
-            release_ids = [get_content_release_id(self._publication_slug)]
+            release_id = get_content_release_id(self._publication_slug)
+            releases = [{"id": release_id, "time_period": None}]
         else:
-            release_ids = get_all_release_ids(self._publication_slug)
+            releases = get_all_releases(self._publication_slug)
 
         self.logger.info(
-            "Found %d release(s) for %s", len(release_ids), self._publication_slug
+            "Found %d release(s) for %s", len(releases), self._publication_slug
         )
 
-        for release_id in release_ids:
+        for release in releases:
+            release_id = release["id"]
+            release_time_period = release["time_period"]
             self.logger.info(
                 "Downloading release %s for %s", release_id, self._publication_slug
             )
@@ -134,6 +149,10 @@ class EESDatasetStream(Stream):
                 # Normalise URN column to 'school_urn' for consistency
                 if self._urn_column in record and self._urn_column != "school_urn":
                     record["school_urn"] = record.pop(self._urn_column)
+                # Inject time_period from release metadata if absent (older files
+                # don't include this column — it's only in the filename/release slug)
+                if "time_period" not in record and release_time_period:
+                    record["time_period"] = release_time_period
                 yield record