docs: list hdrinfo in tool summaries

[sit-d]

Summary

• Add hdrinfo to the top-level README tool list.
• Add hdrinfo to the v1.0.0 included-tools changelog list.

Verification

• Ran a Python consistency check that compares root *.c tools against README.md and CHANGELOG.md entries.
• Ran a bounded local Markdown link check for the touched files.

Command output summary:

all C tools are listed in README.md and CHANGELOG.md: errnfo, hdrinfo, modsnap, quuid, rawwhp, rpscan, uwpchar, wchain
local Markdown links in touched files resolve

Notes / Limitations

• Documentation-only change; Windows builds/tests were not run from this Linux cron environment.