v0.15.6

Highlights

• TUI sidebar: four live panels — workspace Git diff summary (green adds / red deletes), per-session token accounting (cache-hit / cache-miss / output), 8 sub-agent slots with real-time states (idle / working / outputting / messaging / reworking), and Goal status with judge state (awaiting / judging / adjudicated).
• Subagent collaboration fixes and alignment: mid-run parent messages are now delivered to structured-output subagents via a bounded delivery turn (no more silently dropped "accepted" messages), and the collaboration prompts now match runtime semantics — timeout degrades to background execution instead of killing the subagent, rework guidance steers with specifics, and every sub-agent profile explains capability constraints and its own spawn abilities.
• Web UI: exits when no browser connects within the idle window.
• Tools: normalized Bash approval rules into command family templates.
• Usage panel redesigned with an aligned table layout.
• Bumped all workspace packages to 0.15.6.

Validation

• Typecheck passed.
• Agent core tests passed.
• TUI tests passed.