fix(dynostore): fix 3 partial-failure bugs found by object_store fault injection

CLAUDE.md

@@ -140,6 +140,7 @@ Lake features: `parquet`, `iceberg`, `delta` - enable writing schema-backed topi
 - Tests in `nisshi-broker` run against multiple backends: InMemory, Lite (libSQL), Postgres, SlateDb
 - `nisshi-broker`, `nisshi-sans-io` and `nisshi-service` each build one integration-test binary, `it`. To add a test file, create `tests/it/<name>.rs` and declare it with `pub mod <name>;` in `tests/it/main.rs`; Cargo ignores undeclared files, and the `every_test_file_is_declared` test fails if one is missed. Gate backend-specific tests with `#[cfg(feature = "...")]` on a module, not `required-features`. Run one file's tests with a name filter, e.g. `cargo nextest run -p nisshi-broker --all-features -E 'test(/^fetch::/)'`
 - Give each feature its own test file. Put the tests of one feature or one Kafka API in one file under `tests/it/`, named after it. Tests for a new feature go in a new file, not at the end of a file about another subject. A reader then finds them by name, and a name filter on the module selects them.
+- Assert a pattern with `assert_matches!(value, pattern)` from std (`use std::assert_matches;`, stable since Rust 1.96, no crate needed), not `assert!(matches!(value, pattern))` or the `assert_matches` crate. On failure it prints the value, and it reads as one assertion. Nothing enforces this yet, and some older tests still use `assert!(matches!(..))`; leave those alone unless you're already editing them.
 - `nisshi-smoke-test` runs the real Kafka CLI tools (in a `$KAFKA_IMAGE` container) against a broker, and stays out of `just test`; run it with `just smoke <engine>`. Its containers use the host network, so on macOS it needs Docker Desktop with host networking turned on. Its tests talk to the shared broker through `KafkaCli::shared()`, or start their own with `Broker::isolated()`, and each uses its own topic and group names (`nisshi_smoke_test::unique_name`). A test that applies only to some engines is gated with `#[cfg(feature = "<engine>")]` or `#[cfg(any(...))]` on the engines' features, never with `cfg(not(...))`, because `just clippy` turns every feature on and would never compile it. S3 runs only `topic_lifecycle`, selected by the `smoke-s3` profile in `.config/nextest.toml`. A test that fails because of an open bug is marked `#[ignore = "<what is broken>"]`, or `#[cfg_attr(feature = "<engine>", ignore = "...")]` if it fails only on some engines. CI skips it, local runs still run it (`run.sh` passes `--run-ignored all` outside CI), and the change that fixes the bug removes the attribute
 - Single-file test targets with specific feature requirements (e.g. `nisshi-schema`'s `berg`) use `required-features` in their `Cargo.toml`
 

Cargo.toml

@@ -78,14 +78,13 @@
 anyhow = "1.0.94"
 apache-avro = "0.21.0"
 arrow = { version = "58" }
-assert_matches = "1.5.0"
 async-trait = "0.1.86"
 backoff = {version = "0.4.0", features = ["tokio"]}
 bytes = { version = "1", features = ["serde"] }
 cached = "4.0.1"
 chrono = "0.4"
 clap = { version = "4.5.57", features = ["derive", "env"] }
 condtype = "1.3.0"
 console = "0.16.2"
 convert_case = "0.12.0"
 crc-fast = "1.8.0"
@@ -99,7 +98,7 @@
 # builds against. Pin to 1.1.0 until deltalake bumps its buoyant_kernel dep.
 buoyant_kernel_derive = "=1.1.0"
 deltalake = { version = "0.32", features = ["datafusion", "s3"] }
 digest = "0.11.3"
 dotenv = "0.15.0"
 fake = "5.1.0"
 flate2 = "1.1"
@@ -165,7 +164,7 @@
 snap = "1.1.1"
 socket2 = "0.6.5"
 syn = { version = "3.0.3", features = ["extra-traits", "full"] }
 nisshi = { version = "0.7.0-pre.3", path = "nisshi", default-features = false }
 nisshi-auth = { version = "0.7.0-pre.3", path = "nisshi-auth", default-features = false }
 nisshi-broker = { version = "0.7.0-pre.3", path = "nisshi-broker", default-features = false }
 nisshi-cat = { version = "0.7.0-pre.3", path = "nisshi-cat", default-features = false }
@@ -194,8 +193,9 @@
 tokio-postgres-rustls = "0.13.0"
 tokio-rustls = "0.26.4"
 tokio-util = { version = "0.7", features = ["full"] }
+traceforge = "0.2"
 tracing = "0.1"
 tracing-core = { version = "0.1" }
 tracing-opentelemetry = "0.34.0"
 tracing-subscriber = { version = "0.3", features = ["env-filter", "json"] }
 turso = "0.7.1"

nisshi-broker/Cargo.toml

@@ -70,7 +70,6 @@ uuid.workspace = true
 
 [dev-dependencies]
 anyhow.workspace = true
-assert_matches.workspace = true
 object_store.workspace = true
 pbkdf2.workspace = true
 rcgen.workspace = true
@@ -81,3 +80,5 @@ slatedb.workspace = true
 nisshi-schema.workspace = true
 nisshi-storage.workspace = true
 crc-fast.workspace = true
+nisshi-storage-dynostore = { workspace = true, features = ["test-support"] }
+traceforge.workspace = true