refactor(gui): copy-free settings shell; ui-settings-general owns ownerless copy

The shell is now a pure composition face: no dictionaries, no locale
dependency, and three new chrome content seats (settings.trigger /
settings.header / settings.close) whose slot content also carries the
accessible names (trigger text, dialog aria-labelledby, visually hidden
close label). ui-settings-general returns as the owner of copy that
belongs to no single feature: chrome content, the General section with
its item slot, and the settings dictionaries. Slot types split homes —
trigger/header/close/section live in the shell contract; the
settings.general.item entry moves to the locale package (the common
dependency of every item registrant), with ui-theme consuming it
through a re-export seam; the verbatim duplicate merges are gone and
the dependency graph is a clean DAG.

packages/client/locale/src/client/index.ts

@@ -15,6 +15,7 @@ import { createLanguageRowStore } from './settings-store.ts'
 
 export type { LanguageRowComponentProps, LanguageRowInjected } from './LanguageRow.tsx'
 export type { LanguageOptionRow, LanguageRowState } from './settings-store.ts'
+export type { SettingsGeneralItemOwnerProps } from './settings-contract.ts'
 
 /** Translate a key with optional params. */
 export type Translate = (key: string, params?: Record<string, unknown>) => string

packages/client/locale/src/client/settings-contract.ts

@@ -1,18 +1,26 @@
 /**
- * Settings-surface slot merge consumed by this package's Language row. The
- * AUTHORITATIVE home for 'settings.general.item' is the ui-settings contract
- * (declaring is claiming: the shell's General entry declares the slot); this
- * file repeats the entry verbatim because the shell consumes ctx.locale
- * (project reference ui-settings -> locale), so importing the shell's types
- * from here would close a reference cycle. TypeScript declaration merging
- * rejects diverging duplicates, so every program that sees both copies (the
- * shell's own build, the client aggregate) enforces identity.
+ * The `settings.general.item` slot type — one preference row inside the
+ * settings General section, contributed by the feature plugin that owns the
+ * preference (locale → Language, ui-theme → Appearance). Options: `id` (row
+ * key), `order` (row position). Rows draw their own internals (row layout,
+ * separators via CSS); the section column only stacks them.
+ *
+ * TYPE HOME RATIONALE: the slot is declared at runtime by
+ * ui-settings-general's General entry, but its type lives here — this
+ * package is the common dependency of every item registrant (any settings
+ * row carries copy, so every registrant already depends on locale), whereas
+ * the declarer's own contract is unreachable for locale/ui-theme without a
+ * reference cycle.
  */
 declare module '@deepseek-ai/dsh-client-ui-slots' {
   interface SlotMap {
-    /** One preference row inside the General section (duplicate-identical merge; authority: ui-settings contract). */
-    'settings.general.item': { kind: 'list'; scope: 'root'; owner: { children?: never } }
+    /** One preference row inside the settings General section (see module JSDoc). */
+    'settings.general.item': { kind: 'list'; scope: 'root'; owner: SettingsGeneralItemOwnerProps }
   }
 }
 
-export {}
+/** Owner share of a General preference row (the section supplies nothing). */
+export interface SettingsGeneralItemOwnerProps {
+  /** Marker field: item owner props are intentionally empty. */
+  children?: never
+}