docs(agents): archive P1 aggregation barrier

[blakinio]

Purpose

Complete the mandatory separate lifecycle closeout after P1 aggregation PR #184 protected-merged.

Exact scope

• add the final archived OTC2-20260803-playability-p1-aggregation record with accepted P2 graph, findings, exact validation and merge evidence;
• remove the corresponding active task record.

No product code, workspace, lockfile, workflow, dependency, deployment or production change.

Evidence

• barrier PR docs(playability): aggregate P1 and define staged P2 #184 merged as 95d18ca4e97920d1418a41762b86d92b7cf9516d;
• exact head be59ec0f7583f03c5b8b948b477b22ccb0cf5f7e passed Rust Client 30772190456, Windows job 91561164137, Supply Chain job 91561164122;
• repository CI 30772190563, required job 91561261981: PASS;
• ready-state CI 30772355379, required job 91561703246: PASS;
• exactly two lifecycle paths change, behind_by=0;
• comments, reviews and review threads are clean;
• all P1 shared leases are released.

Next gate

Only after this archive PR merges may the coordinator launch the first P2 producer. The first serialized integration owner is SIMULATION-SNAPSHOT; it begins on exclusive paths and requests only the minimal Cargo workspace/lockfile lease after focused validation.