Remove 9 files (913 lines) from the code-driven synthesis pipeline that
was superseded by the agent-driven approach in phases 6-8.
Phases 3/5 built: collectCouncilResults → formatForSynthesis →
buildSynthesisPrompt → formatFindingsForUser → buildDelegationPrompt.
Phases 6-8 replaced with: launch → background_output → Athena
synthesizes in conversation → switch_agent. The old pipeline was
never wired into runtime and all consumers were other dead code.
Also simplifies executeCouncil to return CouncilLaunchResult (task IDs
+ failures) instead of reading stale task status via collectCouncilResults.
Deleted: council-result-collector, synthesis-types, synthesis-prompt,
synthesis-formatter, findings-presenter, delegation-prompts (+ 4 tests).
Cleaned: CouncilMemberStatus, AgreementLevel, CouncilMemberResponse,
CouncilExecutionResult types from types.ts.
ismeth
497e6414d3