fix(athena): harden council members — compaction recovery, block TodoWrite, analysis mode

- Add session.compacted handler in BackgroundManager to prevent premature
  task completion after compaction (defer first post-compaction idle)
- Explicitly block TodoWrite/TodoRead for council members in all sync
  points (AgentConfig permission + session tools + prompt instructions)
- Add council member prefix check to todo-continuation-enforcer skip list
  to prevent infinite continuation loops on completed council members
- Add optional analysis mode (solo/delegation) question to Athena setup:
  solo = thorough but heavier, delegation = fast via explore/librarian
- Allow call_omo_agent in council member allow-list for delegation mode
- Update COUNCIL_MEMBER_PROMPT with TodoWrite prohibition and delegation
  addendum for when delegation mode is selected
- Update prepare_council_prompt tool with mode parameter

src/shared/agent-tool-restrictions.ts

@@ -58,7 +58,8 @@ const AGENT_RESTRICTIONS: Record<string, Record<string, boolean>> = {
   // - src/agents/athena/council-member-agent.ts (AgentConfig permission format — allow-list)
   // - src/plugin-handlers/tool-config-handler.ts (allow/deny string format)
   // Keep all three in sync when modifying.
-  // Council members use an allow-list: only read-only analysis tools are permitted.
+  // Council members use an allow-list: read-only analysis + optional call_omo_agent delegation.
+  // TodoWrite/TodoRead explicitly denied to prevent uncompletable todo loops.
   // Prompt file lives in .sisyphus/tmp/ (inside project) so no external_directory needed.
   "council-member": {
     "*": false,
@@ -70,6 +71,9 @@ const AGENT_RESTRICTIONS: Record<string, Record<string, boolean>> = {
     lsp_symbols: true,
     lsp_diagnostics: true,
     ast_grep_search: true,
+    call_omo_agent: true,
+    todowrite: false,
+    todoread: false,
   },
 }