git:20260716.89f3513 to git:20260724.cb0170c

8 added, 15 removed. Audit A to A.

# Utilities

- General-purpose utility functions with unit tests.

+ General-purpose helpers with co-located tests.

- ## Structure

+ ## Entry points

- ```

- utils/

- ├── utils.go, file.go, network.go, slice.go, string.go, ...

- ├── reexec/ # Self-reexec for upgrades (platform-tagged command_*.go)

- ├── sets/ # Generic set types (int, string)

- └── syncx/ # Generic sync.Map wrapper

- ```

+ Package root (`utils.go`, `file.go`, …) plus `reexec/`, `sets/`, `syncx/`.

- ## Rules

+ ## Non-obvious rules

- - Prefer a co-located `*_test.go` for each non-trivial `.go` file (platform-tagged `reexec/command_*.go` may share package-level tests).

- - Use `utils.CheckSingleton()` for thread-safe single init.

- - Use `utils.SignalHandler()` to obtain the signal channel (blocks on SIGTERM/SIGINT; also watches SIGHUP).

- - Markdown for browser display: `MarkdownToSafeHTML` (not raw `MarkdownToHTML` + `templ.Raw`).

+ - Prefer `*_test.go` per non-trivial `.go` file (`reexec/command_*.go` may share package tests)

+ - `CheckSingleton()` for thread-safe single init; `SignalHandler()` for SIGTERM/SIGINT (+ SIGHUP)

+ - Browser markdown: `MarkdownToSafeHTML` (not raw `MarkdownToHTML` + `templ.Raw`)

- ## Commands

+ ## Testing

```bash

go test ./pkg/utils/...

```