fix(report): a tally is not a verdict, and "1 device(s)" is not a sentence

[gclluch]

The HTML report is written for someone who did not run the tool - a housemate, a landlord, whoever administers the router. Its headline was 192.168.1.0/24 - 6 info: subnet notation that reader does not read, and a count of a severity level they have never heard of. It also made "nothing needs doing" and "act today" look like the same kind of statement, which are the two furthest-apart things in the document.

• The report now leads with a verdict sentence and keeps the tally one line down, next to the subnet and scan id. Verdicts grade by severity rather than by rule - tying the critical line to "reachable from the internet" reads better today and lies the first time a second critical rule lands.
• The terminal keeps the bare tally. Whoever typed the command has the context to read one, and density is what a terminal line is for.
• (s) markers no longer reach a reader. A rule cannot know its own count, so the templates keep the marker and pluralise resolves it in finding(), where the count is finally known - across all five fields, including the evidence the rules build with the same marker.
• Two titles carried real verb disagreement (1 service(s) ... are bound, 1 other device(s) ... are reachable). Reworded to read at any count rather than teaching the helper about verbs.

Rule prose is untouched.