docs: make ENS use-case commands runnable; tighten docs checks and deterministic reference generation

[MontrealAI]

Motivation

• Fix non-runnable example test invocations in the ENS use-case walkthrough so copy/paste commands actually execute the targeted ENS test files.
• Improve documentation validation to catch missing sections, malformed Mermaid blocks, broken relative links, and unsafe SVG content.
• Make the generated ENS reference deterministic and more precise about file/line anchors so CI can reliably validate documentation parity.

Description

• Replaced npm test -- <file> examples in docs/INTEGRATIONS/ENS_USE_CASE.md with direct Truffle file-targeted commands (npx truffle test --network test test/adminOps.test.js and npx truffle test --network test test/mainnetHardening.test.js).
• Revised and tightened prose across docs/INTEGRATIONS/ENS.md, docs/INTEGRATIONS/ENS_ROBUSTNESS.md, and docs/INTEGRATIONS/ENS_USE_CASE.md to clarify trust boundaries, configuration model, and runbooks.
• Enhanced scripts/docs/check-ens-docs.mjs to validate required sections/snippets, require a minimum number of Mermaid blocks, perform stricter SVG sanity checks (namespace, no scripts/external hrefs, no NULs), and improve relative link verification.
• Updated scripts/docs/generate-ens-reference.mjs to filter non-existent source files, produce deterministic output (fixed generated timestamp), use stable sorting/uniqueness, and emit file/line anchors in the generated docs/REFERENCE/ENS_REFERENCE.md.
• Added README links to the ENS docs and adjusted a few minor formatting/labeling details in generated reference and robustness docs.

Testing

• Ran npm run docs:ens:check which performs the new doc integrity checks (sections, Mermaid blocks, SVG, links, and reference generation) and it passed.
• Executed the generated-reference validation by running node scripts/docs/generate-ens-reference.mjs and comparing output to the committed docs/REFERENCE/ENS_REFERENCE.md, which matched (no stale reference error).
• Ran node scripts/check-no-binaries.mjs to ensure no forbidden binary additions; it passed.
• No contract/runtime tests were required for this documentation-only change.

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Codex Task