chore: release v0.15.0 (2026.5.28) (#34008)

* chore: release v0.15.0 (2026.5.28)

The Velocity Release. Run_agent.py refactor (16k→3.8k LOC, -76%),
kanban grows into a multi-agent platform (104 PRs), cold-start perf wave
continues (-240ms / -47% per-turn function calls / -195ms per tool call),
session_search rebuilt (4500x faster, no LLM), promptware defense lands,
Bitwarden Secrets Manager integration, two new image_gen providers
(Krea 2, FAL plugin port), Nous-approved MCP catalog, OpenHands skill,
ntfy as 23rd messaging platform, deep xAI integration round.
15 P0 + 65 P1 closures. 747 PRs, 1,302 commits, 321 contributors.

* chore(release): bump acp_registry/agent.json to 0.15.0 (sync with pyproject)

acp_registry/agent.json

@@ -1,7 +1,7 @@
 {
   "id": "hermes-agent",
   "name": "Hermes Agent",
-  "version": "0.14.0",
+  "version": "0.15.0",
   "description": "Self-improving open-source AI agent by Nous Research with ACP editor integration, persistent memory, skills, and rich tool support.",
   "repository": "https://github.com/NousResearch/hermes-agent",
   "website": "https://hermes-agent.nousresearch.com/docs/user-guide/features/acp",
@@ -9,7 +9,7 @@
   "license": "MIT",
   "distribution": {
     "uvx": {
-      "package": "hermes-agent[acp]==0.14.0",
+      "package": "hermes-agent[acp]==0.15.0",
       "args": ["hermes-acp"]
     }
   }