chore(main): release 0.15.0-alpha

[github-actions]

🤖 I have created a release beep boop

0.15.0-alpha (2026-05-21)

Features

• add send_message tool, fix send_file sub-session routing (c550a2c)
• add send_message tool, fix send_file sub-session routing, strengthen NL task translation (c034f39)
• deliver proactive sub-session results to opted-in rooms (bc9cb55)

Bug Fixes

• address Copilot PR review — deduplicate web broadcast, handle web_ threads in proactive fan-out, clarify config comment (365cccd)
• address Copilot PR review — propagate is_proactive in all SubSessionState paths, improve exception logging (d09eba6)
• address PR review — store Matrix event_bus sub IDs, fix restart_self category in docs (9f4d00a)
• address PR review round 2 — keep send_file categorized, use exclude_names (04a48e7)
• propagate is_proactive in nested aggregation delivery path (d2c2d8d)
• protect skill merge targets from contradictory delete instructions (4e7e044)
• protect skill merge targets from contradictory deletes (798232e)
• reject sub_xxx thread IDs as non-routable in delivery thread resolution (3743006)
• update Signal event_bus subscription comment to reflect both events (6ab3d4c)
• web interface bugs — HTTP status codes, system prompt fallback, frontend error handling (faa6e86)
• web interface bugs — proper HTTP status codes, system prompt fallback, frontend error handling (10c47fa)

Dependencies

• actions: bump googleapis/release-please-action from 4 to 5 (3068596)
• python: bump aiohttp from 3.13.3 to 3.13.4 (774cf14)
• python: bump anthropic from 0.86.0 to 0.87.0 (4612ffa)
• python: bump idna from 3.11 to 3.15 (984007e)
• python: bump json-repair from 0.58.6 to 0.58.7 (fefa1fb)
• python: bump openai from 2.29.0 to 2.30.0 (6de65d9)
• python: bump requests from 2.32.5 to 2.33.0 (72b262f)
• python: bump ruff from 0.15.7 to 0.15.8 (523a489)
• python: bump urllib3 from 2.6.3 to 2.7.0 (8a12347)

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