feat(#2092): migrate Qwen Code onto EoS imperative adapter + native subagents + SubagentStart (ADR-1239)

Fold all runtime==='qwen'/isQwen logic branches (skill-priority frontmatter,
branding/path rewrites, legacy commands/gsd cleanup, hyphen-namespace
normalization, RUNTIME_CONTENT_DISPATCH, hooks-surface label) into
descriptor-driven runtime.hostBehaviors on capabilities/qwen/capability.json,
read via _hostBehaviors(). Shared claude/qwen/hermes legacy-migration branches
in install-engine.cts folded to descriptor flags (claude+hermes descriptors
updated; FALLBACK_HOST_BEHAVIORS.claude floored). Byte-identical golden parity
for qwen/hermes/claude(global+local).

UPGRADE 1: native .qwen/agents/*.md subagent projection — new agents
artifact-layout kind + convertClaudeAgentToQwenAgent converter (name +
description + tools YAML block list; color/model dropped). qwen routed onto
the descriptor-driven agents path (_DESCRIPTOR_AGENTS_RUNTIMES).
UPGRADE 2: SubagentStart hook wired into extendedHookEvents + the
descriptor-gated hook-writer loop (activates only for qwen).

Tests: qwen-imperative-reference (adapter/axes/fail-closed/hostBehaviors +
no runtime==='qwen' source-grep across 4 files) + qwen-upgrades (agents file
validity + SubagentStart mirrors SubagentStop, descriptor-gated). Docs matrix
+ how-to updated; changeset added.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

capabilities/antigravity/capability.json

@@ -89,6 +89,9 @@
       "stateIO": "filesystem",
       "transport": "mcp",
       "runtime": "go"
+    },
+    "hostBehaviors": {
+      "reviewerCli": true
     }
   }
 }

capabilities/claude/capability.json

@@ -95,7 +95,11 @@
       ],
       "ownsClaudePaths": true,
       "nativeModelAliases": true,
-      "skillsGlobalOnboarding": true
+      "skillsGlobalOnboarding": true,
+      "legacyCommandsGsdInstallMigration": true,
+      "legacyCommandsGsdUninstall": "global",
+      "hyphenNameAgentBody": true,
+      "reviewerCli": true
     }
   }
 }

capabilities/codex/capability.json

@@ -78,7 +78,8 @@
       "tomlConfigInstall": true,
       "cleanupSkillSidecars": true,
       "agentTomlFiles": true,
-      "frontmatterDialect": "codex"
+      "frontmatterDialect": "codex",
+      "reviewerCli": true
     }
   }
 }

capabilities/cursor/capability.json

@@ -114,7 +114,8 @@
         "stop",
         "subagentStart",
         "subagentStop"
-      ]
+      ],
+      "reviewerCli": true
     }
   }
 }

capabilities/hermes/capability.json

@@ -63,7 +63,10 @@
         "Claude Code": "Hermes Agent",
         ".claude/": ".hermes/"
       },
-      "reapplyCommand": "gsd-update --reapply (mention the skill name)"
+      "reapplyCommand": "gsd-update --reapply (mention the skill name)",
+      "legacyCommandsGsdInstallMigration": true,
+      "legacyCommandsGsdUninstall": true,
+      "hyphenNameAgentBody": true
     },
     "hostIntegration": {
       "embeddingMode": "imperative",

capabilities/opencode/capability.json

@@ -99,7 +99,8 @@
       "skipHomePrefixSubstitution": true,
       "skipSettingsUi": true,
       "skipUpdateBannerCommand": true,
-      "skipCodexSkillsManifest": true
+      "skipCodexSkillsManifest": true,
+      "reviewerCli": true
     }
   }
 }

capabilities/qwen/capability.json

@@ -28,6 +28,14 @@
           "nesting": "nested",
           "recursive": false,
           "converter": "convertClaudeCommandToClaudeSkill"
+        },
+        {
+          "kind": "agents",
+          "destSubpath": "agents",
+          "prefix": "gsd-",
+          "nesting": "flat",
+          "recursive": false,
+          "converter": "convertClaudeAgentToQwenAgent"
         }
       ],
       "local": [
@@ -38,6 +46,14 @@
           "nesting": "nested",
           "recursive": false,
           "converter": "convertClaudeCommandToClaudeSkill"
+        },
+        {
+          "kind": "agents",
+          "destSubpath": "agents",
+          "prefix": "gsd-",
+          "nesting": "flat",
+          "recursive": false,
+          "converter": "convertClaudeAgentToQwenAgent"
         }
       ]
     },
@@ -52,7 +68,8 @@
     "extendedHookEvents": [
       "SubagentStop",
       "Stop",
-      "PreCompact"
+      "PreCompact",
+      "SubagentStart"
     ],
     "hostIntegration": {
       "embeddingMode": "imperative",
@@ -70,6 +87,15 @@
       "stateIO": "filesystem",
       "transport": "mcp",
       "runtime": "node"
+    },
+    "hostBehaviors": {
+      "skillPriorityFrontmatter": true,
+      "brandingRewrites": { "CLAUDE.md": "QWEN.md", "Claude Code": "Qwen Code", ".claude/": ".qwen/" },
+      "legacyCommandsGsdCleanup": true,
+      "legacyCommandsGsdInstallMigration": true,
+      "legacyCommandsGsdUninstall": true,
+      "hyphenNameAgentBody": true,
+      "reviewerCli": true
     }
   }
 }