feat(rules): user permanent rules — writing style, web building, web security (BDR-085)

Three rules/ files from the user's permanent-rules text:
- writing-style.md (always-on): em-dash ban, no it's-not-X-it's-Y, no
  emoji, no decorative bold, no reflex triads, no hedging chains, slop
  vocabulary ban, sentence-length variety, deliverable self-check.
  Scope carve-outs keep caveman registries, code comments, skill
  templates intact.
- web-building.md (path-scoped): design anti-default list + public-site
  done checklist (report missing items, never invent them).
- web-security.md (path-scoped): browser-exposed keys, service-key/client
  split, RLS, server-side auth, IDOR, cookie flags, field minimization,
  rate limiting — extends §Security, no dup of the core.
Project CLAUDE.md rules/ doctrine: 320-budget exception for standalone
always-on user rule sets.

CLAUDE.md

@@ -17,7 +17,9 @@ A rule WITH `paths:` YAML frontmatter (glob list) loads lazily — only when
 Claude reads a file matching a glob; a rule WITHOUT it loads at session
 start, same cost as the global memory. Extract from CLAUDE.global.md only
 what can be path-scoped (the token win) or what is generated; always-on
-doctrine stays in CLAUDE.global.md. `paths:` globs match against the
+doctrine stays in CLAUDE.global.md. Exception: a standalone user-authored
+rule set that would bust the 320-line density budget may live here WITHOUT
+`paths:` (always-on load) — writing-style.md (BDR-085). `paths:` globs match against the
 CURRENT project's tree — a broad glob (e.g. `rules/**`) can fire in foreign
 projects; keep rule bodies tiny.
 Docs: https://code.claude.com/docs/en/memory.md#path-specific-rules