Add changelog for Citus v14.2.0

Release prep for **citus v14.2.0** from `release-14.0`.

DESCRIPTION: add changelog for 14.2.0

All version-bearing files (configure.ac, configure, citus.control,
citus_columnar.control, multi_extension.out and the 14.1-1 -> 14.2-1
migration scripts) were already bumped in 152fdf4 (#8635), so this is a
single-file CHANGELOG addition.

### Changelog entries (user-visible only)

* #8621 - citus_internal.distribute_object() repair UDF
* #8625 - citus.allow_unsafe_insert_select_pushdown GUC
* #8566 (via #8694) - skip 2PC for single-statement single-shard procedures
* #8587 - object ownership for more citus-internal UDFs
* #8638 (via #8653) - re-range sequences when promoting a clone node
* #8651 (via #8656) - drop orphaned Citus local table shard copies
* #8497 - wrong results when recursive planning projects columns as NULL
* #8692 (via #8700) - UPDATE/DELETE with shard key equality + false predicate
* #8594 (via #8714) - race condition in shard cleanup
* #8498 (via #8715) - type mismatch with COLLATE + type cast
* #8556 (via #8716) - segfault in EXPLAIN with LEFT JOIN + subqueries
* #8465 (via #8718) - CREATE EXTENSION IF NOT EXISTS ownership error
* #8561 (via #8717) - crash on writable standby coordinator

CI/test-infra, SQL-plumbing and version-bump commits intentionally excluded.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 61fba89e-b958-4d9f-902e-eb76004b5580

Author: ihalatci-msft

CHANGELOG.md

@@ -1,3 +1,51 @@
+### citus v14.2.0 (August 5, 2026) ###
+
+* Adds `citus_internal.distribute_object()`, a superuser-only repair UDF
+  that manually propagates an existing object to the worker nodes as a
+  distributed object (#8621)
+
+* Adds `citus.allow_unsafe_insert_select_pushdown` to allow shard-local
+  batched `INSERT ... SELECT` pushdown for colocated tables, for workloads
+  that call expensive batch-oriented UDFs (#8625)
+
+* Avoids coordinated transactions for single-statement single-shard
+  procedure calls by determining 2PC requirements through PL/pgSQL static
+  analysis instead of a runtime counter (#8566)
+
+* Enforces object ownership for more citus-internal UDFs (#8587)
+
+* Re-ranges sequences to the new group id when promoting a clone node so
+  that distributed, reference and Citus local tables keep globally-unique
+  sequence values (#8638)
+
+* Drops orphaned Citus local table shard copies on a worker promoted from
+  a clone of the coordinator (#8651)
+
+* Fixes wrong query results when recursive planning projects
+  restriction-referenced columns as NULL, such as for
+  `NOT (x IS DISTINCT FROM y)` (#8497)
+
+* Fixes a crash and `could not find valid entry for shard` errors when
+  planning `UPDATE` or `DELETE` on a distributed table whose `WHERE`
+  clause combines distribution key equality with an always-false
+  predicate (#8692)
+
+* Fixes a race condition in shard cleanup where a stale catalog snapshot
+  could cause an in-use shard to be dropped (#8594)
+
+* Fixes a type mismatch when `COLLATE` is used together with a type cast
+  in distributed queries (#8498)
+
+* Fixes a segfault in `EXPLAIN` for queries with a `LEFT JOIN` and
+  correlated subqueries (#8556)
+
+* Fixes an unexpected "must be owner of extension" error on
+  `CREATE EXTENSION IF NOT EXISTS` for an already-distributed extension
+  by skipping the ownership check in that case (#8465)
+
+* Fixes a crash on a writable standby coordinator when writing to a
+  coordinator-local shard (#8561)
+
 ### citus v14.1.0 (May 14, 2026) ###
 
 * Adds support for running several DDLs for schema-based sharding from any