dockerize Files

Changelog

• [3b1589] chore(deps): bump Go module dependencies
• [db5f3d] chore(docker): bump build image to golang 1.27.2
• [000b4c] chore(lint): enable errcheck
• [7c0ac4] docs(main): add package comment and doc comments for Context, Env, HttpHeader and Config
• [f8b68f] docs(readme): correct replace, contains and ReadDir template docs
• [d3af0a] docs(readme): document -version and -wait-retry-interval flags
• [36c46a] docs(readme): document accepted -wait URL forms
• [0e45c8] docs(readme): document flag combinations as a behaviour change
• [0196b1] docs(readme): fix jsonQuery example JSON and query path
• [489ce0] docs(readme): state that both -delims delimiters are required
• [4b8922] fix(exec): log signal and kill errors other than process already done
• [12a000] fix(main): reject a zero or negative timeout with wait
• [66e885] fix(main): reject a zero or negative wait retry interval
• [4ba1e9] fix(main): reject empty -delims halves and -template destinations
• [97059d] fix(main): reject flags that need a companion option
• [6f5f8f] fix(main): reject invalid -wait-http-header names and values
• [9cbd08] fix(main): skip environment entries without '=' in Env
• [d66b2b] fix(main): validate -wait URLs per scheme at startup
• [a09dcb] fix(tail): handle t.Stop and write errors in tailFile
• [2619f5] fix(template): check temp file cleanup errors
• [ceeda3] fix(template): check the error from closing the destination file
• [052e5e] fix(template): reject non-positive step in loop
• [616538] fix(template): return error from parseUrl instead of exiting
• [75b045] fix(template): write rendered files atomically and skip subdirs
• [cb699b] fix(test): check the error from closing test listeners
• [3b3522] fix(wait): skip the request after a failed NewRequest
• [272b26] fix: make TestExistsErrorIncludesFilePath pass in every environment
• [217258] fix: update Go to 1.27.3 and refresh dependencies
• [f8e0b6] refactor(template): merge sprig and dockerize funcs with maps.Copy
• [edebe3] refactor: use errors.AsType for exit code extraction
• [c48224] refactor: use sync.WaitGroup.Go for wait and signal goroutines
• [2ba157] test(e2e): handle errors from file writes, listeners and cleanup
• [867da6] test(exec): assert delivered signal and SIGKILL fallback
• [c76d2b] test(exec): cover signalling exited and live processes
• [2e67a1] test(tail): cover missing file, named pipe and poll mode
• [0bd91e] test(tail): cover write errors and fix errcheck hits
• [736823] test(template): cover failed render and subdirectory in dirs
• [30e0f1] test(template): cover full output and file mode when writing to a file
• [752249] test(wait): cover waitForHTTP request errors, status codes and headers
• [726406] test(wait): reuse tail test log helpers to fix duplicate declarations