docs(timeline): update Day 96 notes with latest PR/issue counts (2026-04-06)

docs/timeline.md

@@ -5046,13 +5046,15 @@ Deadline risk: HIGH
 
 **Notes**
 
-- Day 96 update (2026-04-06). New build session #3775 launched. Massive PR merge/close wave: open PRs dropped from 183 to 108 (-75 PRs merged/closed).
+- Day 96 update (2026-04-06). New build session #3775 launched. Massive PR merge/close wave: open PRs dropped from 183 to 108 (-75 PRs merged/closed) at session start.
 - Milestone progress since Day 95: M3 61%→65% (228→246 closed, +18), M4 57%→60% (104→109 closed, +5), M5 64%→68% (126→136 closed, +10), M6 55%→55% (180→180, stable), M7 41%→43% (138→152 closed, +14), M8 41%→46% (359→418 closed, +59), M9 25%→28% (118→131 closed, +13).
 - Milestone totals also grew: M3 376→377, M4 183→183 (stable), M5 196→199, M6 325→327, M7 335→350, M8 880→917 (+37 new issues), M9 465→467.
-- Open bugs: ~878 (stable from Day 95). Open issues: ~1612 total across all milestones.
+- Open bugs: ~878 (stable from Day 95). Open issues: ~1858 total (growing — agent-driven issue creation).
 - PR #3774 (Click 8.2+ compatibility fix, closes #3773) opened by Jeff. CI failures in push-validation and coverage checks. Priority issue #3776 created to track resolution.
+- Open PRs grew from 108→114 as agents opened new fix/feature PRs (#3788 docs, #3911 plan-lifecycle rollback, and others).
 - Session 3 remains active with 16 parallel workers and ~71 total concurrent agents.
 - All milestones M3-M7 remain overdue. M8 and M9 have no deadlines and are in active development.
+- New issues created by agents: #3835 (PureGraph topological sort bug), #3912 (action.py refactor), and others — continued agent-driven expansion.
 
 
 #### Milestone forecast