refactor(app): consolidate isEditableTarget into utils/dom

Merge the two implementations from session.tsx and command.tsx into a
single shared function that covers tagName checks, contentEditable,
and ancestor traversal.

packages/app/src/context/command.tsx

@@ -4,6 +4,7 @@ import { createSimpleContext } from "@opencode-ai/ui/context"
 import { useDialog } from "@opencode-ai/ui/context/dialog"
 import { useLanguage } from "@/context/language"
 import { useSettings } from "@/context/settings"
+import { isEditableTarget } from "@/utils/dom"
 import { Persist, persisted } from "@/utils/persist"
 
 const IS_MAC = typeof navigator === "object" && /(Mac|iPod|iPhone|iPad)/.test(navigator.platform)
@@ -177,14 +178,6 @@ export function formatKeybind(config: string): string {
   return IS_MAC ? parts.join("") : parts.join("+")
 }
 
-function isEditableTarget(target: EventTarget | null) {
-  if (!(target instanceof HTMLElement)) return false
-  if (target.isContentEditable) return true
-  if (target.closest("[contenteditable='true']")) return true
-  if (target.closest("input, textarea, select")) return true
-  return false
-}
-
 export const { use: useCommand, provider: CommandProvider } = createSimpleContext({
   name: "Command",
   init: () => {

packages/app/src/pages/session.tsx

@@ -33,6 +33,7 @@ import { usePrompt } from "@/context/prompt"
 import { useComments } from "@/context/comments"
 import { SessionHeader, NewSessionView } from "@/components/session"
 import { same } from "@opencode-ai/util/array"
+import { isEditableTarget } from "@/utils/dom"
 import { createOpenReviewFile } from "@/pages/session/helpers"
 import { createScrollSpy } from "@/pages/session/scroll-spy"
 import { SessionReviewTab, type DiffStyle, type SessionReviewTabProps } from "@/pages/session/review-tab"
@@ -614,11 +615,6 @@ export default function Page() {
     saveLabel: language.t("common.save"),
   }))
 
-  const isEditableTarget = (target: EventTarget | null | undefined) => {
-    if (!(target instanceof HTMLElement)) return false
-    return /^(INPUT|TEXTAREA|SELECT|BUTTON)$/.test(target.tagName) || target.isContentEditable
-  }
-
   const deepActiveElement = () => {
     let current: Element | null = document.activeElement
     while (current instanceof HTMLElement && current.shadowRoot?.activeElement) {

packages/app/src/utils/dom.ts

@@ -1,3 +1,12 @@
+export function isEditableTarget(target: EventTarget | null | undefined) {
+  if (!(target instanceof HTMLElement)) return false
+  if (/^(INPUT|TEXTAREA|SELECT|BUTTON)$/.test(target.tagName)) return true
+  if (target.isContentEditable) return true
+  if (target.closest("[contenteditable='true']")) return true
+  if (target.closest("input, textarea, select")) return true
+  return false
+}
+
 export function getCharacterOffsetInLine(lineElement: Element, targetNode: Node, offset: number): number {
   const r = document.createRange()
   r.selectNodeContents(lineElement)