style: use semantic line breaks and remove soft wraps

[ajbeck]

Prepares the repository for public release by replacing column-width wrapping with semantic line breaks.

Changes

• Prose (all Markdown, Go comments, and the consumer test source): one sentence per line, plus a break after ; between independent clauses, following Semantic Linefeeds, SemBr and the existing AGENTS.md style. No column limit is applied. Code fences, tables, headings, Go directives, indented doc-comment blocks and // Output: sections are untouched.
• Code: multi-line composite literals that packed several elements per line now have one element per line. Literals and calls that were wrapped only for width are joined onto one line. The RFC 7515 Appendix A.2 test-vector constants are single string literals.
• Five compounds split across old wraps (e.g. issuer/ client/resource) now read without the stray space.

Validation

• Every Markdown file renders to identical HTML with goldmark + GFM, after collapsing whitespace, except for the five compound-word fixes.
• Every Go file has an identical token stream, with comment wrapping normalized and paragraph and verbatim structure preserved, except for added/removed trailing commas, the RFC constant merge and one compound-word fix in a comment.
• gofmt -l . shows no files. go vet ./..., go mod verify, go test -race ./..., sh scripts/check-consumer.sh, both Linux cross-builds and git diff --check pass. The nested docs/probes/iamproof module vets and tests clean.

Limitations

• Splitting packed literals one element per line also separates a few intentional pairings in test tables, such as case-alias header pairs in response_headers_test.go.
• Sentence detection is heuristic. Abbreviations like e.g. are excluded and split points were reviewed, but long sentences remain long lines by design.