fix(office-ui): native progress parity, ui_state lock hardening, approval-card idempotency

Native agent progress panel (company mode):
- ws_handler: filter runtime bookkeeping noise (turn/status/member_inbox_updated),
  keep tool_completed as tool_call, thinking summary previews content,
  preserve raw thinking_delta fragments (no strip; skip whitespace-only)
- frontend progressLog: summarize thinking by content preview; merge thinking
  by detail only so the 'Thinking' label never splices into text
- AgentProgressBlock: add bottom "Show more (N earlier steps)" toggle

ui_state.db "database is locked" hardening:
- ws_handler: isolate engine progress/kanban/runtime-event callbacks so UI
  persistence failures never crash work items
- chat_store: busy_timeout, _retry_locked backoff, idempotent insert_message
  (INSERT OR REPLACE), create_channel read-before-write to stop poll writes
- server: flock single-instance guard for `opc ui` per OPC home

Approval card duplicate-click bug:
- EscalationPanel: disable buttons on click with Submitting state and 30s
  reconnect fallback
- ws_handler: stale-escalation branch checks real card status (new
  chat_store.get_checkpoint_message); already-resolved cards get an accurate
  "already handled (decision: X)" reply without being re-marked stale;
  dedup identical helper messages within 120s to stop reply spam

Company mode prompt:
- add soft guidance that the runtime monitors state and re-activates roles,
  so leaders need not poll work items after delegation/review

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

opc/plugins/office_ui/frontend_src/lib/progressLog.ts

@@ -27,9 +27,9 @@ function mergeText(left: string, right: string, kind: 'thinking' | 'tool_call'):
 }
 
 function summarizeThinking(detail: string, fallback: string): string {
-  void detail
-  void fallback
-  return 'Thinking'
+  const text = detail.trim().replace(/\s+/g, ' ')
+  if (!text) return fallback || 'Thinking'
+  return text.length > 120 ? `${text.slice(0, 120).trimEnd()}...` : text
 }
 
 function normalizeProgressEntry(entry: ProgressEntry): ProgressEntry {
@@ -84,7 +84,10 @@ function isDuplicateProgress(left: ProgressEntry, right: ProgressEntry): boolean
 
 function mergeProgress(left: ProgressEntry, right: ProgressEntry): ProgressEntry {
   if (left.type === 'thinking') {
-    const detail = mergeText(left.detail ?? left.summary, right.detail ?? right.summary, 'thinking')
+    // Merge detail text only: summary is a label/preview ("Thinking",
+    // truncated excerpt), so falling back to it would splice label text
+    // into the middle of the merged thinking stream.
+    const detail = mergeText(left.detail ?? '', right.detail ?? '', 'thinking')
     return {
       timestamp: right.timestamp,
       type: 'thinking',