docs: SW Dotum / Web Noto Sans KR font rule in AI guides and README

- Common AI_GUIDE (synced copies in ui / sw / org-chart / org-chart-react ai/): mixed-use rule 1 adds the font split
  (SW = Dotum, Web = Noto Sans KR, OrgChart keeps its own) and forbids copying one package's font into another area.
- SW AI_USAGE / DESIGN_RULES / VIEWER / COMPOSITION_PATTERNS / Example J: Dotum is the default (no "approval pending"),
  SW screens use SWTheme and SW tokens, no Web font copy, synthesized-bold width note; example override = Malgun Gothic.
- README: SW default Dotum, Web default Noto Sans KR.

packages/sw/ai/examples/ExampleJ-Theme.tsx

@@ -1,8 +1,8 @@
 // Example J — SW theme tokens (both modes). The only official way to change SW tokens: `style` (or the program's own
 // class) on the OUTERMOST SW scope. Here one <SWTheme> wraps the viewer screen, so the header, its dropdowns, More,
 // and every panel read the same value. Portals leave the DOM tree: wrap their content in <SWTheme> with the same style.
-// The font below is a placeholder for a program decision: the SW default stays Noto Sans KR (a Dotum default is
-// pending design approval), so only set it when the program has decided to.
+// The font below is a placeholder for a program decision: the SW default is Dotum (2026-10-20) and needs no token,
+// so only set it when the program has decided on another font. Never copy the Web UI font (Noto Sans KR) here.
 import { useState, type CSSProperties } from "react"
 import { createPortal } from "react-dom"
 import {
@@ -12,7 +12,7 @@ import {
 
 /** One theme object for the screen and for every portal. Token names only (`--hm-sw-*`), never `hm-sw-*` classes. */
 export const appSWTheme = {
-  "--hm-sw-header-font-family": '"Noto Sans KR", "Malgun Gothic", "Apple SD Gothic Neo", sans-serif',
+  "--hm-sw-header-font-family": '"Malgun Gothic", "Apple SD Gothic Neo", sans-serif',
 } as CSSProperties
 
 export function ExampleJTheme({ onEvent }: { onEvent?: (name: string) => void }) {