fix(storage): preserve heal failures and timeout responses (#8462)

* fix(storage): preserve heal failures and timeout responses

Stop repairs with no writable target before opening source readers. Consolidate target failure aggregation, preserve typed causes, and distinguish all-ignored diagnostics from actual successful nil entries. Map typed disk timeouts to retryable S3 responses without changing quorum decisions.

Co-Authored-By: heihutu <heihutu@gmail.com>

Co-Authored-By: zhi22915 <qiuzgang@gmail.com>

* refactor(heal): unify staging failure cleanup

Route data-stage failures through one local result boundary after temporary
readers and writers are released. Preserve typed report failures, outer
reconstruction errors, partial repair, and the existing commit fences.

Exercise actual source loss after second-part writer admission using the
existing test pause registry. Assert all staged parts are removed, committed
metadata stays unchanged, and restoring the source allows a full-byte retry.

Co-Authored-By: heihutu <heihutu@gmail.com>
Co-Authored-By: zhi22915 <qiuzgang@gmail.com>

---------

Co-authored-by: zhi22915 <qiuzgang@gmail.com>
Co-authored-by: heihutu <heihutu@gmail.com>
Co-authored-by: Chris <anzhengchao@gmail.com>

scripts/error-other-format-baseline.txt

@@ -59,7 +59,7 @@
 7|crates/ecstore/src/set_disk/core/io_primitives.rs
 1|crates/ecstore/src/set_disk/mod.rs
 3|crates/ecstore/src/set_disk/ops/bitrot_self_verify.rs
-2|crates/ecstore/src/set_disk/ops/heal.rs
+1|crates/ecstore/src/set_disk/ops/heal.rs
 8|crates/ecstore/src/set_disk/ops/multipart.rs
 2|crates/ecstore/src/set_disk/ops/object.rs
 3|crates/ecstore/src/set_disk/read.rs