docs(Settings): tighten materialized_views_ignore_errors description

Make the retry+deduplication advice apply only to the default (failing)
mode where the client actually has a failure signal. Mention that the
enabled mode trades view completeness for forward progress and point at
the CREATE VIEW docs for the full partial-delivery semantics.

Follow-up to ClickHouse#106044 (comment)

Author: CheSema

src/Core/Settings.cpp

@@ -4728,7 +4728,7 @@ This setting is useful for ensuring that materialized views do not contain dupli
     DECLARE(Bool, materialized_views_ignore_errors, false, R"(
 If enabled, exceptions thrown while pushing data to a dependent materialized view (in its `SELECT` or in the inner table sink) are logged as a warning and the `INSERT` statement succeeds. If disabled (default), such an exception propagates and the `INSERT` statement fails.
 
-This setting controls only error reporting. It does not roll back a write to the source table, and it does not guarantee that the original block has, or has not, already been committed to the source table when an error occurs in a dependent view's pipeline. Retry the `INSERT` if you need at-least-once delivery to dependent views, and combine retries with the insert deduplication feature (see `insert_deduplicate` and `deduplicate_blocks_in_dependent_materialized_views`) to achieve exactly-once delivery on retry.
+This setting controls only error reporting. It does not roll back a write to the source table, and it does not guarantee whether the original block has already been committed to the source table when an error occurs in a dependent view's pipeline. When disabled (default), the `INSERT` fails on a view error — retry it with insert deduplication (`insert_deduplicate`, `deduplicate_blocks_in_dependent_materialized_views`) for exactly-once delivery to the source table and all dependent views. When enabled, the `INSERT` reports success despite partial delivery to failing views and their downstream chains; use this only when source-table writes must not be blocked by view-side problems (for example, `system.*_log` tables). See the `CREATE VIEW` docs for full semantics.
 )", 0) \
     DECLARE(Bool, ignore_materialized_views_with_dropped_target_table, false, R"(
 Ignore MVs with dropped target table during pushing to views