chore: release v0.15.0

[ArthurBernard]

[0.15.0] - 2026-07-14

Added

• Daemon logs are real logs — rotated (midnight, 14-day retention), ISO-8601 local timestamps with numeric tz offset, manifest logging: section; tick errors carry tracebacks. (feat: daemon logging spine — rotated, timestamped, manifest-configurable #226)
• Per-unit daemon log trail — rebalance summaries (counters partitioning the universe), round-up/skip LegDecision.reasons at INFO, order submits/refusals, fill lines with fee asset, unit transitions; idle ticks add zero per-unit lines. (feat: per-unit daemon log trail — rebalance summaries, skip reasons, order/fill lines #227)
• Tick timing measured and pinned (closes the daemon-logging epic) — heartbeat carries the tick duration (WARN on overrun); explicit APScheduler coalesce=True/max_instances=1/misfire_grace_time=interval (the 1 s default grace silently skipped late ticks — the measured source of the ~74 s-vs-60 s cadence shortfall); additive /api/health + /api/strategies timing fields. (feat: tick timing — durations, pinned scheduler semantics, health metrics #228)

Test plan

• CI green on develop (all three leaf PRs merged on green)
• CI green on this PR