fix: harden and de-slop the merged contribution batch

Follow-ups promised on merge, plus review findings on the batch itself:

- chat: task-tool output now respects the 512KiB render cap; quick-open
  icon is visible at rest on coarse pointers and reachable by keyboard
  (row keydown no longer swallows inner-button Enter/Space); composer
  inline-code decoration drops the metric-shifting padding; a btw fork
  send carries only the boundary instruction, never the promotion notice
- sync: cascade revert/unrevert aborts busy descendants, busy state is
  read from every child store at the moment of use; rule 9 documents
  redo clearing all descendant revert markers
- electron: renderer recovery keeps memory-eviction (a valid
  render-process-gone reason) and both windows share one
  attachRendererRecovery helper
- vscode: process registry is a thin re-export of the web module
  (provider-env-aliases precedent) with ordered register/unregister
  writes and an awaited close
- server/cli: managed-process registry takes injectable deps (fixes the
  unreaped-orphans ReferenceError), corrupt settings errors name the
  file, getWorktrees test restores console.warn
- tests: module-mock harnesses removed (AgentsSidebar, SettingsView
  mobile focus — behaviors stay live but uncovered, accepted trade),
  QuestionMarkdown asserts rendered DOM
- i18n: German gains the debug-panel request keys, Japanese/German drop
  removed worktree keys, Ukrainian unit spacing fixed
- changelog: Copilot AI Credits entries (main + VS Code)

packages/ui/src/components/chat/ChatInput.tsx

@@ -36,7 +36,7 @@ import { ReviewFlowDialog, type ReviewFlowExecution } from '@/components/session
 import { BtwPanel } from './btw/BtwPanel';
 import { useBtwPanelState } from './btw/useBtwPanelState';
 import { wasPromotedBtwSession } from '@/lib/sessionBtwMetadata';
-import { BTW_BOUNDARY_INSTRUCTION, BTW_PROMOTION_NOTICE, destroyBtwSession, startBtwSession, type BtwSessionRef } from '@/lib/btw';
+import { buildBtwSyntheticTexts, destroyBtwSession, startBtwSession, type BtwSessionRef } from '@/lib/btw';
 import { AttachedFilesList, AttachedVSCodeFileChips, ActiveEditorFileSuggestion } from './FileAttachment';
 import { lazyWithChunkRecovery } from '@/lib/chunkLoadRecovery';
 import type { ToolPopupContent } from './message/types';
@@ -1134,12 +1134,8 @@ const ChatInputComponent: React.FC<ChatInputProps> = ({
             composerText: !queuedOnly && inputSnapshot.hasContent ? inputSnapshot.message : null,
             composerAttachments: attachedFiles,
             inlineComments: drafts,
-            // btw mode: the boundary rides with every send, not just the
-            // first one, so the inherited transcript stays reference material
-            // for the whole side conversation.
             syntheticTexts: [
-                ...(isBtwActive ? [BTW_BOUNDARY_INSTRUCTION] : []),
-                ...(isPromotedBtwSession ? [BTW_PROMOTION_NOTICE] : []),
+                ...buildBtwSyntheticTexts({ isBtwActive, isPromotedBtwSession }),
                 ...(syntheticParts?.map((part) => part.text) ?? []),
             ],
             linkedIssue: linkedIssue