fix: resolve logic errors in ahm heal module (#788)

* fix: resolve logic errors in ahm heal module

- Fix response publishing logic in HealChannelProcessor to properly handle errors
- Fix negative index handling in DiskStatusChange event to fail fast instead of silently converting to 0
- Enhance timeout control in heal_erasure_set Step 3 loop to immediately respond to cancellation/timeout
- Add proper error propagation for task cancellation and timeout in bucket healing loop

* fix: stabilize performance impact measurement test

- Increase measurement count from 3 to 5 runs for better stability
- Increase workload from 5000 to 10000 operations for more accurate timing
- Use median of 5 measurements instead of single measurement
- Ensure with_scanner duration is at least baseline to avoid negative overhead
- Increase wait time for scanner state stabilization

* wip

* Update crates/ahm/src/heal/channel.rs

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* refactor: remove redundant ok_or_else + expect in event.rs

Replace redundant ok_or_else() + expect() pattern with
unwrap_or_else() + panic!() to avoid creating unnecessary Error
type when the value will panic anyway. This also defers error
message formatting until the error actually occurs.

* Update crates/ahm/src/heal/task.rs

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* fix(ahm): fix logic errors and add unit tests

- Fix panic in HealEvent::to_heal_request for invalid indices
- Replace unwrap() calls with proper error handling in resume.rs
- Fix race conditions and timeout calculation in task.rs
- Fix semaphore acquisition error handling in erasure_healer.rs
- Improve error message for large objects in storage.rs
- Add comprehensive unit tests for progress, event, and channel modules
- Fix clippy warning: move test module to end of file in heal_channel.rs

* style: apply cargo fmt formatting

* refactor(ahm): address copilot review suggestions

- Add comment to check_control_flags explaining why return value is discarded
- Fix hardcoded median index in performance test using constant and dynamic calculation

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

AGENTS.md

@@ -8,12 +8,14 @@ The workspace root hosts shared dependencies in `Cargo.toml`. The service binary
 
 ## Build, Test, and Development Commands
 Run `cargo check --all-targets` for fast validation. Build release binaries via `cargo build --release` or the pipeline-aligned `make build`. Use `./build-rustfs.sh --dev` for iterative development and `./build-rustfs.sh --platform <target>` for cross-compiles. Prefer `make pre-commit` before pushing to cover formatting, clippy, checks, and tests.
+Always ensure `cargo fmt --all --check`, `cargo test --workspace --exclude e2e_test`, and `cargo clippy --all-targets --all-features -- -D warnings` complete successfully after each code change to keep the tree healthy and warning-free.
 
 ## Coding Style & Naming Conventions
 Formatting follows the repo `rustfmt.toml` (130-column width). Use `snake_case` for items, `PascalCase` for types, and `SCREAMING_SNAKE_CASE` for constants. Avoid `unwrap()` or `expect()` outside tests; bubble errors with `Result` and crate-specific `thiserror` types. Keep async code non-blocking and offload CPU-heavy work with `tokio::task::spawn_blocking` when necessary.
 
 ## Testing Guidelines
 Co-locate unit tests with their modules and give behavior-led names such as `handles_expired_token`. Integration suites belong in each crate’s `tests/` directory, while exhaustive end-to-end scenarios live in `crates/e2e_test/`. Run `cargo test --workspace --exclude e2e_test` during iteration, `cargo nextest run --all --exclude e2e_test` when available, and finish with `cargo test --all` before requesting review. Use `NO_PROXY=127.0.0.1,localhost HTTP_PROXY= HTTPS_PROXY=` for KMS e2e tests.
+When fixing bugs or adding features, include regression tests that capture the new behavior so future changes cannot silently break it.
 
 ## Commit & Pull Request Guidelines
 Work on feature branches (e.g., `feat/...`) after syncing `main`. Follow Conventional Commits under 72 characters (e.g., `feat: add kms key rotation`). Each commit must compile, format cleanly, and pass `make pre-commit`. Open PRs with a concise summary, note verification commands, link relevant issues, and wait for reviewer approval.