perf(master-data): remove zombie fixture file and add bulk-insert fast path

The previous commit moved Main type of activity data to master_data/ but left
the original fixture file in place — Frappe's sync_fixtures reads every .json
in app/fixtures/ regardless of the hooks.py fixtures list, so the file was
still being imported on every migrate (3499 DELETE+INSERTs). Delete it.

Also adds a bulk-insert fast path (db_insert chunks of 500) to sync_master_data
for the large first-run case on fresh sites, so the new sync is faster than
the legacy fixture import even when populating an empty table.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

taxes_az/master_data/sync.py

@@ -111,8 +111,31 @@ def sync_master_data(doctype: str, json_path: str, key_field: str = "name") -> d
 
     inserted = updated = deleted = disabled = skipped = 0
 
-    for key, rec in target.items():
-        if key not in existing:
+    to_insert = [(key, rec) for key, rec in target.items() if key not in existing]
+    to_check = [(key, rec) for key, rec in target.items() if key in existing]
+
+    # Bulk-insert fast path for the large first-run case (avoid 10k+ ORM .insert()
+    # round-trips). Uses db_insert() per doc — skips before_insert/after_insert
+    # hooks, which is appropriate for static master data.
+    BULK_THRESHOLD = 100
+    if len(to_insert) >= BULK_THRESHOLD:
+        for key, rec in to_insert:
+            doc = frappe.new_doc(doctype)
+            if key_field == "name":
+                doc.name = key
+                doc.flags.name_set = True
+            else:
+                doc.set(key_field, key)
+            for field in value_fields:
+                if field in rec:
+                    doc.set(field, rec[field])
+            doc.db_insert()
+            inserted += 1
+            if inserted % 500 == 0:
+                frappe.db.commit()
+        frappe.db.commit()
+    else:
+        for key, rec in to_insert:
             doc = frappe.new_doc(doctype)
             if key_field == "name":
                 doc.name = key
@@ -126,8 +149,8 @@ def sync_master_data(doctype: str, json_path: str, key_field: str = "name") -> d
             doc.flags.ignore_links = True
             doc.insert(ignore_if_duplicate=True)
             inserted += 1
-            continue
 
+    for key, rec in to_check:
         db_row = existing[key]
         diff = {f: rec[f] for f in value_fields if f in rec and (db_row.get(f) or "") != (rec[f] or "")}
         if diff: