feat(seed): provision taxonomy buckets (infra) + exam-corpus loader skeleton

infra (buckets.py): add cc.public / cc.institutes / cc.admin to the bucket
provisioner alongside cc.examboards; make initialize_buckets idempotent
(already-exists treated as success). Bucket provisioning stays in infra init.

new (seed_exam_corpus.py): manifest-driven loader scaffold that USES the buckets
(does not create them) — validate -> upload to cc.examboards (canonical path) ->
upsert eb_specifications/eb_exams -> optional user test subset -> optional
--first-sweep auto-map pass. TODOs marked for the gathering task to complete.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

run/initialization/buckets.py

@@ -46,7 +46,7 @@ def initialize_buckets() -> dict:
                     file_size_limit=1000 * 1024 * 1024,  # 1GB
                 )
             },
-            # Exam Board files
+            # Exam Board files (admin-curated public exam corpus: QP/MS/insert/ER + specs)
             {
                 "id": "cc.examboards",
                 "options": CreateBucketOptions(
@@ -55,6 +55,34 @@ def initialize_buckets() -> dict:
                     file_size_limit=1000 * 1024 * 1024,  # 1GB
                 )
             },
+            # ── Storage taxonomy bins (access scoped by RLS on bucket + leading path segment; RLS = D1) ──
+            # Platform-managed public/shared assets (readable by all authenticated users).
+            {
+                "id": "cc.public",
+                "options": CreateBucketOptions(
+                    name="Classroom Copilot Public",
+                    public=False,
+                    file_size_limit=1000 * 1024 * 1024,  # 1GB
+                )
+            },
+            # Institute-scoped operational assets: cc.institutes/{institute_id}/...
+            {
+                "id": "cc.institutes",
+                "options": CreateBucketOptions(
+                    name="Classroom Copilot Institutes",
+                    public=False,
+                    file_size_limit=1000 * 1024 * 1024,  # 1GB
+                )
+            },
+            # Platform-admin-only assets, seeds, intake/staging for unidentified papers.
+            {
+                "id": "cc.admin",
+                "options": CreateBucketOptions(
+                    name="Classroom Copilot Admin",
+                    public=False,
+                    file_size_limit=1000 * 1024 * 1024,  # 1GB
+                )
+            },
         ]
         
         results = {}
@@ -81,11 +109,17 @@ def initialize_buckets() -> dict:
                     logger.error(f"Failed to create bucket: {bucket['id']}")
                     
             except Exception as e:
-                results[bucket["id"]] = {
-                    "status": "error",
-                    "error": str(e)
-                }
-                logger.error(f"Error creating bucket {bucket['id']}: {str(e)}")
+                # Idempotent: an already-existing bucket is not a failure on re-run.
+                if any(s in str(e).lower() for s in ("already exists", "duplicate", "resource already")):
+                    results[bucket["id"]] = {"status": "exists", "result": str(e)}
+                    success_count += 1
+                    logger.info(f"Bucket already exists (ok): {bucket['id']}")
+                else:
+                    results[bucket["id"]] = {
+                        "status": "error",
+                        "error": str(e)
+                    }
+                    logger.error(f"Error creating bucket {bucket['id']}: {str(e)}")
         
         # Determine overall success
         if success_count == total_count: