v0.13.6

Added

• (schema) Stabilize optional message IDs (#1372)
• (schema) Stabilize session usage updates (#1371)
• (schema) Stabilize session/delete (#1370)
• (unstable-v2) Remove MCP SSE transport and make stdio opt-in (#1368)
• (unstable-v2) Clean up capability objects (#1367)
• (unstable-v2) Require message IDs in v2 chunks (#1352)
• (unstable-v2) Adopt plan_update as v2 plan shape (#1347)
• (unstable-v2) Remove v2 client filesystem and terminal surface (#1346)

Fixed

• (unstable) Fix plan capability key (#1369)

Other

• (rfd) Add JSON-RPC batch guidance for v2 (#1348)
• (rfd) Split end-turn token usage from session usage (#1345)
• (rfd) Clarify agent-owned message IDs in RFDs (#1344)
• (deps) bump the minor group with 5 updates (#1341)
• Render feature docs in docs.rs (#1331)