7675d010c2
Adds three new skills extracted from mkstack's restructured AGENTS.md and trims the corresponding AGENTS.md sections to match. - nostr-security: XSS threat model, URL and CSS sanitization patterns, author filtering for trust-sensitive queries, NIP-72 moderation walkthrough, and a pre-merge checklist. The skill's references to sanitizeUrl and sanitizeCssString are pointed at Ditto's existing helpers in src/lib/sanitizeUrl.ts and src/lib/fontLoader.ts. - testing: Vitest + TestApp conventions, mocked browser APIs, and the project policy on when (not) to create new test files. - nip85-stats: reference documentation for NIP-85 Trusted Assertion stats (kinds 30382, 30383, 30384) including a ready-to-copy useNip85Stats hook for future use; not currently wired into Ditto. AGENTS.md changes: - Shrink the Nostr Security Model section from a verbose kinds-and-URLs walkthrough into a compact rule list plus a spoof-vs-authors example, with a pointer to the new skill. - Trim the Writing Tests section to the policy + skill pointer, moving the TestApp example and browser-API mocks into the skill. - Demote Loading States / Empty States from a top-level section to a subsection under CRITICAL Design Standards so the document's top-level headings describe domains, not presentation details. Net: AGENTS.md 1654 -> 1480 lines (~10%).