chore(git): merge from master

Author: claude

.github/copilot-instructions.md

@@ -12,8 +12,9 @@ Read and follow the CONTRIBUTING.md file in this repository for all code style c
 - Use `pipe-trait` for chaining through unary functions (constructors, `Some`, `Ok`, free functions, etc.), avoiding nested calls, and continuing method chains — but not for simple standalone calls (prefer `foo(value)` over `value.pipe(foo)`)
 - Prefer `where` clauses for multiple trait bounds
 - Derive order: std traits → comparison traits → `Hash` → derive_more → feature-gated
-- Custom errors: `#[derive(Debug, Display, Error)]`
+- Error types: only derive `Display` and `Error` from `derive_more` when each is actually needed — not all displayable types are errors
 - Minimize `unwrap()` in non-test code — use proper error handling
 - Install toolchain before running tests: `rustup toolchain install "$(< rust-toolchain)" && rustup component add --toolchain "$(< rust-toolchain)" rustfmt clippy`
 - Run `FMT=true LINT=true BUILD=true TEST=true DOC=true ./test.sh` to validate changes. If a test fails with a hint about `RUSTFLAGS` and `--cfg pdu_test_skip_*`, follow the hint and rerun with the suggested flags.
 - **ALWAYS run the full test suite** (`FMT=true LINT=true BUILD=true TEST=true DOC=true ./test.sh`) before committing, regardless of how trivial the change seems — this includes documentation-only changes, comment edits, config changes, and refactors. The test suite checks formatting, linting, building, tests, and docs across multiple feature combinations; any type of change can break any of these checks.
+- Set `PDU_NO_FAIL_FAST=true` to run all checks instead of stopping at the first failure — this lets you see which checks pass and which fail

AGENTS.md

@@ -12,8 +12,9 @@ Read and follow the CONTRIBUTING.md file in this repository for all code style c
 - Use `pipe-trait` for chaining through unary functions (constructors, `Some`, `Ok`, free functions, etc.), avoiding nested calls, and continuing method chains — but not for simple standalone calls (prefer `foo(value)` over `value.pipe(foo)`)
 - Prefer `where` clauses for multiple trait bounds
 - Derive order: std traits → comparison traits → `Hash` → derive_more → feature-gated
-- Custom errors: `#[derive(Debug, Display, Error)]`
+- Error types: only derive `Display` and `Error` from `derive_more` when each is actually needed — not all displayable types are errors
 - Minimize `unwrap()` in non-test code — use proper error handling
 - Install toolchain before running tests: `rustup toolchain install "$(< rust-toolchain)" && rustup component add --toolchain "$(< rust-toolchain)" rustfmt clippy`
 - Run `FMT=true LINT=true BUILD=true TEST=true DOC=true ./test.sh` to validate changes. If a test fails with a hint about `RUSTFLAGS` and `--cfg pdu_test_skip_*`, follow the hint and rerun with the suggested flags.
 - **ALWAYS run the full test suite** (`FMT=true LINT=true BUILD=true TEST=true DOC=true ./test.sh`) before committing, regardless of how trivial the change seems — this includes documentation-only changes, comment edits, config changes, and refactors. The test suite checks formatting, linting, building, tests, and docs across multiple feature combinations; any type of change can break any of these checks.
+- Set `PDU_NO_FAIL_FAST=true` to run all checks instead of stopping at the first failure — this lets you see which checks pass and which fail

CLAUDE.md

@@ -12,9 +12,10 @@ Read and follow the CONTRIBUTING.md file in this repository for all code style c
 - Use `pipe-trait` for chaining through unary functions (constructors, `Some`, `Ok`, free functions, etc.), avoiding nested calls, and continuing method chains — but not for simple standalone calls (prefer `foo(value)` over `value.pipe(foo)`)
 - Prefer `where` clauses for multiple trait bounds
 - Derive order: std traits → comparison traits → `Hash` → derive_more → feature-gated
-- Custom errors: `#[derive(Debug, Display, Error)]`
+- Error types: only derive `Display` and `Error` from `derive_more` when each is actually needed — not all displayable types are errors
 - Minimize `unwrap()` in non-test code — use proper error handling
 - Install toolchain before running tests: `rustup toolchain install "$(< rust-toolchain)" && rustup component add --toolchain "$(< rust-toolchain)" rustfmt clippy`
 - Run `FMT=true LINT=true BUILD=true TEST=true DOC=true ./test.sh` to validate changes. If a test fails with a hint about `RUSTFLAGS` and `--cfg pdu_test_skip_*`, follow the hint and rerun with the suggested flags.
 - **ALWAYS run the full test suite** (`FMT=true LINT=true BUILD=true TEST=true DOC=true ./test.sh`) before committing, regardless of how trivial the change seems — this includes documentation-only changes, comment edits, config changes, and refactors. The test suite checks formatting, linting, building, tests, and docs across multiple feature combinations; any type of change can break any of these checks.
+- Set `PDU_NO_FAIL_FAST=true` to run all checks instead of stopping at the first failure — this lets you see which checks pass and which fail
 - `gh` (GitHub CLI) is not installed — do not attempt to use it

CONTRIBUTING.md

@@ -198,7 +198,10 @@ where
 
 ### Error Handling
 
-- Define custom error enums with `#[derive(Debug, Display, Error)]` from `derive_more`.
+- Use `derive_more` for error types. Only derive the traits that are actually used:
+  - `Display`: derive when the type needs to be displayed (e.g., printed to stderr, used in format strings).
+  - `Error`: derive when the type is used as a `std::error::Error` (e.g., as the error type in `Result`, or as a source of another error). Not all types with `Display` need `Error`.
+  - A type that only needs formatting (not error handling) should derive `Display` without `Error`.
 - Minimize `unwrap()` in non-test code — use proper error propagation. `unwrap()` is acceptable in tests and for provably infallible operations (with a comment explaining why). When deliberately ignoring an error, use `.ok()` with a comment explaining why.
 
 ```rust

template/ai-instructions/shared.md

@@ -12,8 +12,9 @@ Read and follow the CONTRIBUTING.md file in this repository for all code style c
 - Use `pipe-trait` for chaining through unary functions (constructors, `Some`, `Ok`, free functions, etc.), avoiding nested calls, and continuing method chains — but not for simple standalone calls (prefer `foo(value)` over `value.pipe(foo)`)
 - Prefer `where` clauses for multiple trait bounds
 - Derive order: std traits → comparison traits → `Hash` → derive_more → feature-gated
-- Custom errors: `#[derive(Debug, Display, Error)]`
+- Error types: only derive `Display` and `Error` from `derive_more` when each is actually needed — not all displayable types are errors
 - Minimize `unwrap()` in non-test code — use proper error handling
 - Install toolchain before running tests: `rustup toolchain install "$(< rust-toolchain)" && rustup component add --toolchain "$(< rust-toolchain)" rustfmt clippy`
 - Run `FMT=true LINT=true BUILD=true TEST=true DOC=true ./test.sh` to validate changes. If a test fails with a hint about `RUSTFLAGS` and `--cfg pdu_test_skip_*`, follow the hint and rerun with the suggested flags.
 - **ALWAYS run the full test suite** (`FMT=true LINT=true BUILD=true TEST=true DOC=true ./test.sh`) before committing, regardless of how trivial the change seems — this includes documentation-only changes, comment edits, config changes, and refactors. The test suite checks formatting, linting, building, tests, and docs across multiple feature combinations; any type of change can break any of these checks.
+- Set `PDU_NO_FAIL_FAST=true` to run all checks instead of stopping at the first failure — this lets you see which checks pass and which fail

test.sh

@@ -1,6 +1,22 @@
 #! /bin/bash
 set -o errexit -o pipefail -o nounset
 
+# Validate PDU_NO_FAIL_FAST
+no_fail_fast="${PDU_NO_FAIL_FAST:-false}"
+case "$no_fail_fast" in
+true | false) ;;
+*)
+  echo "error: Invalid value for PDU_NO_FAIL_FAST: $no_fail_fast (expected 'true' or 'false')" >&2
+  exit 1
+  ;;
+esac
+
+# A temporary file is used instead of a variable because run_if and unit are
+# subshells, so variable assignments inside them don't propagate to the parent.
+failure_dir=$(mktemp -d)
+trap 'rm -rf "$failure_dir"' EXIT
+failure_marker="$failure_dir/failed"
+
 run() (
   echo >&2
   echo "exec> $*" >&2
@@ -16,7 +32,19 @@ run_if() (
   condition="$1"
   shift
   case "$condition" in
-  true) run "$@" ;;
+  true)
+    if [[ $no_fail_fast == 'true' ]]; then
+      run "$@" || {
+        exit_status=$?
+        printf 'error: Command failed with exit code %d: ' "$exit_status" >&2
+        printf '%q ' "$@" >&2
+        printf '\n' >&2
+        touch "$failure_marker"
+      }
+    else
+      run "$@"
+    fi
+    ;;
   false) skip "$@" ;;
   *)
     echo "error: Invalid condition: $condition" >&2
@@ -39,3 +67,9 @@ unit --all-features "$@"
 unit --features cli "$@"
 unit --features cli-completions "$@"
 unit --features ai-instructions "$@"
+
+if [[ -f "$failure_marker" ]]; then
+  echo >&2
+  echo 'error: Some checks have failed. Review the output above for details.' >&2
+  exit 1
+fi